A Small Glance to Eberron: Rising from the Last War

First and foremost: I dig Eberron. A lot. It was the setting where the second D&D campaign that I ever played was set up (the first and third ones were homebrewed), and where I really began delving into a shared world. With the most recent release already in my hands, I figured it might be fair to figure out how you can work Paladins in this setting of wide magic, where magitek, pulp and noir reign supreme.

New Races
Changeling: A shapeshifting race, though most of its features are meant for subterfuge. The ability score set-up is nice, allowing you to boost Strength, Dexterity or Constitution while having exceptional Charisma (or, you can have truly exceptional Charisma and middling other scores). The free skill and language proficiencies are nice. That said, their main trait (Shapechanger) is meant to allow you to assume any form, which can be great when you're trying to pass undetected, but you're not exactly talented in subterfuge anyways.
Goblinoids: Yes, we got all three main goblinoids as races! This is important, because goblinoids comprise a great deal of Eberron history. Did you know they actually had an empire and everything!?
Bugbear: Big and nasty. They have a huge boost to Strength and some decent Dexterity, but there's three things that really set them up - first, they're the only class with reach. Second, they got Powerful Build. Third, they can deal some decent damage if you manage to surprise them. Plus, they got free proficiency in Stealth, in case you wanna be stealthy. That said, you'll want to go either Strength or Dexterity (and 9 out of 10 times, you really want Strength; you want Dex if you're going the rare Fencer or Archer path), you'll rarely be able to catch someone by surprise on your own, and if you're wearing non-Mithral heavy armor, you can kiss your Stealth success chances good-bye. I can still take good Strength and reach any time...
Goblin: With Dex and Con, they can make a decent Fencer, and the ability to reposition yourself through bonus action Disengage makes you pretty mobile. Fury of the Small is pretty big, adding a whopping amount of damage equal to your level; at first, it might not seem like much, but a Goblin going nova with this little bugger can pretty much one-shot most creatures, if not all. That said, it's not exactly the most amazing race, and being Small, that means Heavy weapons (the ones that deal more damage) are slightly off-limits.
Hobgoblin: Constitution and Intelligence!? Ugh, why!? Anyways, most of the traits are poor, and for being the most military-inclined, they oddly make good spellcasters. Saving Face is a nice ability that lets you attempt to succeed on a save, but only works on a short rest. For the most part, the one race of the goblinoids that should be the most appropriate for Paladins is the one that's the least.
Kalashtar: These super-pretty humans miss some of their psionic flavor (mostly because WotC is having issues with psionics), but it has a few goodies. The stats aren't as favorable (boost to Charisma, but minor, and the other is Wisdom), resistance to psychic damage (which is pretty rare but painful), advantage on Wisdom saving throws (with your Wisdom save proficiency and your added Charisma, you're most likely never gonna fail such a save), but the one feature I find interesting is Mind Link. As things go, it's wonderful for intra-battle communication; you can essentially relay info to other allies, and have the leader (or the strategist) always in mental contact. Note on Severed from Dreams - you're immune to dream effects, but not to sleep. Keep mind of that.
Orc: Yes, Orc is a race now. It was on Volo's, and here, it's improved. For one, it has stats on the right places (Strength and Constitution), a dangerous move that lets you be really sticky (Aggressive), the useful though not broken Powerful Build, plus two free skill proficiencies in skills that you might actually want to see some use. Orcs are really pretty nice for Paladins, even if they don't add that much to them.
Shifter: One of my favorite races, because it lets you play with werewolf-lites! One thing to realize is that the ability scores are specific to their subraces, sharing only Darkvision, the ability to Shift...and that's it. Speaking of Shifting; it's not gonna be that great if you don't have many short rests, but if you have only One Big Fight, it's super useful.
Beasthide: The meaty ones, they get scores on the right places, proficiency in a very useful skill, and their shift increases their AC (in addition to the temporary HP). Arguably the better of the four.
Longtooth: The scores aren't that great, but you get proficiency in a very useful skill, and their Shift ability gives you a free bonus attack that deals pretty decent damage (1d6 base). Note that Improved Divine Smite and all other weapon modifiers apply to this one.
Swiftstride (Fen): The scores aren't that impressive, but it has several good things. For one, it's one of the few rare ways to get Acrobatics as a bonus skill proficiency. You also become super-slippery and fast, so if you dig movement, this is the one for you. Most Paladins aren't, but the rare Fencer always likes its movement, so there's that.
Wildhunt: Scores in stats that aren't useful, Survival is great but easy to get, and while denying advantage to enemy attackers is great, it's nothing exceptional. Leave this one to the Rangers and Monks.
Warforged: The stars of the setting, these living constructs were meant to be tireless combatants, easy to train and easy to deploy, repair and command. In essence: they're Terminators. Their ability score increases are awesome, since while they have their main stat as Constitution, their other one is floating; add it to Strength, Dexterity or Charisma as you like. Their Construct Resilience gives them superb bonuses, and while they need to "rest", they don't fall unconscious, so they can alert the party on an ambush. Integrated Protection is controversial, since it no longer means the Warforged doesn't need to wear armor, but the benefits are actually very solid - +1 to AC and the inability to have your armor removed, on a class that most likely relies on wearing the heaviest armor possible, is always a positive. Do note that you have to be proficient in the armor, but you don't care because...well, you actually do! You also get a free skill proficiency of any kind, which is superb. Warforged are almost ridiculously close to variant Humans in flexibility.

These are essentially subraces and variants for specific races (namely, the common ones - Dwarf, Elf, Halfling, Human - and some uncommon ones - Gnomes, Half-Elves and Half-Orcs - which were the standard races on the 3.5 PHB. Each subrace or variant grants a specific ability score bonus, a "Guidance"-like effect on specific skills, some minor powers, but most importantly, it offers a list of spells that are added to the spell list of any class you have access to, meaning you can either learn or prepare them. As the Paladin prepares spells, it means it has access to all of these spells. Thus, the worth of the dragonmark clearly will be influenced by the spells on this list.

Detection (Medani): While the flexible score is nice, Paladins don't use Wisdom that much. Access to two very useful Detect spells is great, but the spell list is rather crummy.
Spell List: 1st - detect evil and good, detect poison and disease; 2nd - detect thoughts, find traps; 3rd - clairvoyance, nondetection; 4th - arcane eye, divination; 5th - legend lore
Finding (Tharashk): This mark applies to either Half-Orcs or Humans, and replaces everything they have. It's slightly more useful for Humans because it gives Darkvision. The skills to which the d4 applies are very useful, but the crowning achievement is getting Hunter's Mark 1/long rest, which is formidable if you don't wanna go Oath of Vengeance. That said, the ability scores leave a lot to be desired. (They look like perfect for Clerics...)
Spell List: 1st - faerie fire, longstrider; 2nd - locate animals or plants, locate object; 3rd - clairvoyance, speak with plants; 4th - divination, locate creature; 5th - commune with nature
Handling (Vadalis): Same issue with the Mark of Detection regarding ability scores, but if you plan to deal with animals, beasts and monstrosities, this is your mark. Animal Friendship 1/short rest can be pretty solid, but do note that it requires you to have a pretty high Wisdom score.
Spell List: 1st - animal friendship, speak with animals; 2nd - beast sense, calm emotions; 3rd - beacon of hope, conjure animals; 4th - aura of life, dominate beast; 5th - awaken
Healing (Jorasco): A subrace for Halflings, it grants a boost to Wisdom, which you don't use that much, but it has one of the most controversial spell lists you can field. You also get the ability to cast Cure Wounds and Lesser Restoration once per day (do note that the amount you restore is based on your Wisdom, so it'll most likely be decent, but not impressive). Arguably one of the best Dragonmarks, but mostly because of that spell list.
Spell List: 1st - cure wounds, healing word; 2nd - lesser restoration, prayer of healing; 3rd - aura of vitality, mass healing word; 4th - aura of life, aura of purity; 5th - greater restoration
Hospitality (Ghallanda): Another subrace for Halflings, this one has a weaker spell list (great for utility, but you don't have the slots for it, let's be honest), but a better choice for ability score and gives you a cantrip. Still not enough to save it.
Spell List: 1st - goodberry, sleep; 2nd - aid, calm emotions; 3rd - create food and water, Leomund's tiny hut; 4th - aura of purity, Mordenkainen's magnificent mansion; 5th - hallow
Making (Cannith): The focus on Intelligence really smarts, but it has a pretty interesting spell list. The hallmark of this dragonmark (pun not intended) is getting to use Magic Weapon from 1st level, without concentration. This can work if you're in a dungeon, right after using your short rest.
Spell List: 1st - identify, Tenser's floating disk; 2nd - continual flame, magic weapon; 3rd - conjure barrage (Arc, Thr), elemental weapon; 4th - fabricate, stone shape; 5th - creation
Passage (Orien) (Fen): Focused on being super mobile, this dragonmark grants you a bonus to Dexterity and another stat of your choice. You get a boost to your speed, and the ability to cast Misty Step, which is perfect for when you want to reposition yourself. Insanely good spell list. (Note: this dragonmark got a nerf from its incarnation in Wayfinder's Guide to Eberron, where it had faster speed, the d4 applied to Athletics, and gave you the ability to ignore difficult terrain on a Dash)
Spell List: 1st - expeditious retreat, jump; 2nd - misty step, pass without trace; 3rd - blink, phantom steed; 4th - dimension door, freedom of movement; 5th - teleportation circle
Scribing (Sivis): Gnomes are already the weirdest choices, and here you get a subrace that's just as odd. It has the ability score increase on the right stat (Cha), but the effects aren't as impressive. Message as a cantrip can be pretty amazing if used correctly, and if you're the face, Comprehend Languages is a must.
Spell List: 1st - comprehend languages, illusory script; 2nd - animal messenger, silence; 3rd - sending, tongues; 4th - arcane eye, confusion; 5th - dream
Sentinel (Deneith) (DR): A tough choice, since while it gives great stats to Constitution, you really have to suck up the boost to Wisdom. You get to apply the d4 to two very useful saves, and you gain the ability to use Shield for free. Sadly, it's only applicable once per long rest, alongside the nice Vigilant Guardian effect. (Seriously, why not once on a short rest? Oath of the Crown and Oath of Redemption let you cover up for an ally once per round anyways...) The spell list is pretty boss for a defender, and any way you can add Warding Bond as a Paladin spell is always a bonus. (Note: of all the Dragonmarks, this one received a serious nerf, since the d4 applied to Initiative checks, and Vigilant Guardian was more of a stance, as well as the ability score increases applying to Strength and an additional score)
Spell List: 1st - compelled duel, shield of faith; 2nd - warding bond (DR), zone of truth; 3rd - counterspell, protection from energy; 4th - death ward, guardian of faith; 5th - Bigby's hand
Shadow (Phiarlan/Thuranni): An odd choice, this is the only Elf subrace, but it's an interesting one nonetheless. You get a bonus to Charisma, and the ability to use the incredibly useful Minor Illusion cantrip, plus a 1/long rest Invisibility. The spell list at first isn't as impressive, but the latter spells are just insanely good. If you plan to rely on stealth and be an Elf, this is arguably the better of the elven subraces.
Spell List: 1st - disguise self, silent image; 2nd - darkness, pass without trace; 3rd - clairvoyance, major image; 4th - greater invisibility, hallucinatory terrain; 5th - mislead
Storm (Lyrandar): The second variant of Half-Elf. The stats are fair for Paladins who use Dexterity, and it has a rare resistance (to lightning damage). Gust is a pretty fluffy cantrip, not exactly very useful but has its uses nonetheless. The spell list is unique in that it deals no damage whatsoever, but it's full of crowd control effects which can see a lot of use.
Spell List: 1st - feather fall, fog cloud; 2nd - gust of wind, levitate; 3rd - sleet storm, wind wall; 4th - conjure minor elemental, control water; 5th - conjure elemental
Warding (Kundarak): The only Dwarven subrace, but this one is tailored for Dwarves who want to be more roguish. You get a bonus on Intelligence (aka, dump stat), the spells you get access to are pretty decent but not awesomely so (Alarm is the most useful one since it helps you during your sleep watch; Mage Armor is useful when used on an ally, though), and the spell list is...well, did you know they have access to Armor of Agathys? Color me surprised.
Spell List: 1st - alarm, armor of Agathys; 2nd - arcane lock, knock; 3rd - glyph of warding, magic circle; 4th - Leomund's secret chest, Mordenkainen's faithful hound; 5th - antilife shell

The book has only one new feat, but it's tied to the concept of Dragonmarks.
Aberrant Dragonmark: A very impressive feat. It's essentially Magic Initiate, except it requires no minimum ability score, boosts Constitution (which is always VERY useful), and gives you only one cantrip instead of two. You also get a 1st-level spell, but the spellcasting ability you use is Constitution, which as I have mentioned is always very useful to have high. Since you can choose from the Sorcerer spell list, that means you can choose from the Sword Coast Adventurer's Guide cantrips, including but not limited to Booming Blade. Snatch two useful spells, get your Con boost...oh yeah, and a roleplaying flaw that's more fluff than anything. Seriously - this feat is awesome!

Magic Items
The book has a treasure trove of magic items, most of which are tied to either Dragonmarked characters or Warforged. You also get the rare prosthetic items, which allow you to replace a limb for something just as good, if not cooler. Assume that whatever I don't mention is either on its own section, or is mostly for fluff and thus not very useful.
Arcane Propulsion Arm (UA): Are you willing to cut your arm for it? If you do, you get an awesome item that allows you to throw your punches away. Seriously. Rocket. Punch. That said, it does require attunement, but you deal an amazing amount of damage with your unarmed strikes (1d8, and it's force damage, so resist that!)
Dragonmarked Items: All of these items require attunement to someone who has a specific Dragonmark.
Finder's Goggles (Mark of Finding): Its main use is to add your d4 to Insight checks. The ability to use Locate Creature on the creature is fun, but not amazing.
Keycharm (Mark of Warding): A nifty tool that lets anyone in your party ignore the effect of certain spells you cast (if you're a spellcaster, mostly, though the Alarm and Arcane Lock effects are powers you can manifest without being a spellcaster), That said, it's mostly utility.
Scribe's Pen (Mark of Scribing): It lets you write invisible messages?
Speaking Stone: Aka, magical cellphones. It's located here because you need to have a gnome with the Mark of Scribing to make use of it, but if you have one such stone, you can receive messages from it.
Feather Token: First: it's a common item. Second: it doesn't require attunement. Third: it doesn't require an action. Have at least one at all occasions.
Glamerweave: More of a fashion expression than anything else, but for the most part, the main utility is to get that d4 on Performance or Persuasion checks, and that only works once per day. Great if you're the face of the party, particularly since it doesn't require attunement.
Imbued Wood Focus: Essentially a spellcasting focus, this item's main use is to boost damage from a spell you cast. This includes your smite spells. The damage boost is very, VERY small. If you're looking for options, Fernian Ash, Irian Rosewood, Lammanian Oak and Xorian Wenge are the best. The utility of this item depends on how much you use your spells.
Orb of Shielding: Common, and its effect is small but relatively useful. When you hold an item of this kind, you can spend your reaction to reduce damage by a paltry 1d4. This requires DM adjudication, but if it can apply after damage reductions, it's a much better choice. Otherwise, it's a wash.
Prosthetic Limb: Unlike the Arcane Propulsion Arm, this is mostly meant to replace a lost limb. One of its key benefits is that every limb counts as a single item for purposes of attunement, but on the other hand... Stick to Regenerate.
Symbiotes: All items of this kind are technically considered cursed items, but that's relative. All of these items can't be removed, and usually have a specific negative effect tied to it, but as with most cursed items, they can be minor or heavy.
Belashyrra's Beholder Crown: Magical darkvision is the bee's knees, but the ability to cast certain spells as if they were a wand, with a pretty high DC of 16 for their actions, makes it worthwhile. Do note that there's an issue with Telekinesis, because if you don't have spellcasting, you technically can't use this spell because it references it. Also, the costs are pretty hefty; seven charges for Finger of Death, yet six for Disintegrate?
Dyrrn's Tentacle Whip: Magical whip, no negative effects, +2 to attack and damage rolls, +1d6 extra psychic damage, and stuns on a nat 20. And it can't be disarmed unless your arm is cut, and even then, it might just retract and reappear on your other hand. Other than the shock of having a tentacle flowing from your arm, there's very little drawbacks. Oh yeah, you have disadvantage on attacks against aberrations, but that's what normal weapons are for, right? Right?
Earworm: No, not that kind of earworm. You can use Dissonant Whispers or Detect Thoughts, but if you do, any thoughts you hear are also heard by the nearest daelkyr. A DC of 15 for Dissonant Whispers is pretty boss.
Kyrzin's Ooze: Gain resistance to acid AND poison, immunity to the poison condition, and you can either become amorphous (and squeeze through everything) or gain a decent acid breath weapon. Do note that the penalty is severe; if you die, your body is destroyed, and you just added a new and very annoying enemy for your party to fight. I'd say, though, that the costs outweigh the benefits.
Living Armor: This is a strange form of armor - it can be any kind (even Full Plate), with a +1 to AC, and it also grants resistance to three pretty nasty damage types (necrotic, poison and psychic). The drawback, however, is immense - it demands half of your HD every day, or gain one level of exhaustion. I'll give it a good score because it can't be removed.
Living Gloves: One of the few, if not the only, items that grant you Expertise. You also gain proficiency in the skill, if you lack it. You can also choose which kind of item to become proficient with, and apply your Expertise. That said, the proficiencies applicable are Sleight of Hand, thieves' tools, one artisan's tools or one musical instrument. It's half useful, but losing one attunement slot for it kinda hurts.
Ventilating Lungs: They don't replace a lost set of lungs, but rather modify them. (Wait; isn't that cyberware? You mean, you added Shadowrun to my Eberron? RPGception!) The main benefit is getting water breathing, vacuum breathing, and advantage on saves against aerial contaminants. You can also use Gust of Wind 1/day, which isn't so bad.
Warforged Components: All of these components require you to be a Warforged. That's basically it.
Armblade: It's a magic weapon that can't be disarmed, but it has to be one-handed and specifically melee. (YMMV on whether you can throw it, but convention says no.) You can retract or extend the weapon as a bonus action, which hurts because you can't use your free item interaction for the same. The best use for it is when you have a ranged weapon, since you can then switch weapons during the same turn.
Docent: The best way to explain it is, it's basically Cortana. No, seriously - for Warforged, this is essentially artificial intelligence on a small sphere, which you can grant your Warforged in order to gain some useful skills and benefits, except you don't get control of most of your functions. For the most part, it's a translator (understands Common, Giant, and up to four other languages, of which it can learn by just hearing them), a defibrillator (yep; it's meant to stabilize you), a +7 bonus on four Intelligence skills, and the option to either cast Detect Evil or Good, or Detect Magic, but the docent chooses when to use it. While it's mostly for utility, a docent is insanely useful - in fact, it's probably too useful, and attunement is not enough.
Wand Sheath: Amazing item. Lets you store one wand, which you can then release and use, except that unlike Armblades, the hand remains free. Also, the wand and the sheath are considered a single item for purposes of attunement, so you get to save attunement slots! And, you can't be disarmed.