I'm still gonna post the other 4 builds I mentioned, but it's a bit delayed since... I maaaay have written up the guide-length post, only to accidentally click off the reply page. Whoops. But here's another build to tide you over that I think you'll like. Please let me know what you think!
The Ancestral Nightmare is a flexible tank that, unlike the vast majority of Barbarians, allows you to lock down opponents in both melee and at range. It can grapple multiple opponents at a time while still wielding a sword and shield, or it can circumvent the usual limitations for thrown weapons to harass people with javelins while providing allies with Resistance, Disadvantage to be hit, damage reduction, and damage retributionÖ all at the same time.
Build 8: The Ancestral Nightmare (Javelin Master / Grappler Tank)
Simic Hybrid Ancestral Guardian Barbarian 16 / Battle Master 3 / Rogue 1
Stats (Point Buy): 16 Str / 14 Con / 14 Dex / 13 Wis / 10 Cha / 8 Int
ASIs: Max Strength, Resilient (+1 Wisdom), Lucky
Sample Maneuvers: Commanderís Strike, Precision Attack, Tripping Attack
Expertise: Athletics, one other skill of your choice
A problem and a solution:
If you want to use throwing weapons, you can only draw one object a turn without cutting into your action economy, which creates a problem for those with Extra Attack. This usually makes Barbarians sad, because theyíre hungry for ranged options.
If you want to be a grappler, you canít normally use a shield or a two-handed weapon because you need to keep a hand free to grab your opponent. This too usually makes Barbarians sad, because they want to shove someone, grapple them, and then beat the bejesus out of them, while simultaneously being as efficient as possible in sponging damage.
Simic Hybrid solves both of these problems by making you into a tentacle monster at level 5.
While these limbs canít actually throw your javelins, they can hold a bundle of Ďem, which is good enough because switching items between your limbs is a non-action. And they can grapple multiple people at a time while leaving both hands free for sword and board. And not only that, but you get what is essentially Tavern Brawler as a bonus feat, which means we donít have to spend our precious ASIs looking for something to do with our bonus action.
On top of your extra limbs, Simic Hybrid also gives you Darkvision, ideal stats, and a selection of useful mobility skills (Manta Glide will let you convert falling distance into speed boosts, Climbing speed will help you drag your grappled people up walls and then drop them for damage and prone, swimming willÖ uhÖ be relevant in an aquatic campaign).
At range: You throw two weapons including your Dueling bonus, and your target is harassed by your ancestors. This means that if they want to target anyone else in your party, they have to deal with Resistance and Disadvantage and damage reduction from Spirit Shield and guaranteed damage from Vengeful Ancestors. Heck, at that point you can just put yourself out of range, since youíre the only one they can attack for full value. Unfortunately, you still don't get your Rage bonus to thrown weapon damage (since a "melee weapon attack using Strength" and an "attack with a melee weapon using Strength" count as something different according to Crawford), but that's Barbarian for ya.
Once you have your fighter levels, you also have the option of using Commanderís Strike to hand the local Rogue an off-turn Sneak Attack, further boosting your ranged DPR. And of course Action Surge.
Either way, youíre better off than pretty much every other Barbarian who finds themselves stuck out of melee range for a turn.
In melee: Youíre a superior grappler, able to grab multiple enemies (with Advantage, and later Expertise), shove Ďem to the ground, and still wail on them while wielding a shield. And your ability to perform at range means that you can do things like nail someone on one side of the map with a javelin (making them the target of your Ancestral Protectors) then lock down a second foe near you.
The Rogue dip is primarily to pick up Expertise, which will give you some non-combat utility and make your grapple/shove checks basically guaranteed (scaling as high as +17+Advantage).
The Battle Master levels are becauseÖ well, how do I put this. The Barbarian chassis kinda forgets to scale its damage much in the later levels. And while this buildís main job isnít being a DPR factory, itís nice to be able to unload from time to time. Battle Master will give you a decent burst damage option and some extra tools via maneuvers.
Your nova damage at tier 4 works out to 86.9 DPR vs AC 19 (4 attacks with Action Surge, Advantage from Reckless Attack, any damaging maneuver if you hit or precision attack if you miss), 100.9 DPR with Vengeful Ancestors (plus 14 DPR of damage reduction to the ally, for a total 114.9 average damage shift in your teamís favor, plus Resistance and Disadvantage of course). You can push this a good deal higher with Commanderís Strike depending on your team composition. Your rage damage without maneuvers or Action Surge is 34.5, or 48.5 with Vengeful Ancestors (plus 14 DPR of damage reduction to the ally, for a total 62.5 average damage shift in your teamís favor).
For perspective, a tier 4 Bear-barian entering rage and using GWM with Advantage has only 37.7 DPR vs AC 19, or 46.3 at exactly level 20 (from the capstone). And they donít have a shield, do less at range, or while grappling someone, and donít dramatically reduce damage to their allies. See the difference?
Like all shover/grappler builds, the Ancestral Nightmare synergizes very well with a team that can put down hazards like Spike Growth, Create Bonfire, Wall of Fire, Spirit Guardians, Silence, etc. In fact, you do so even more than usual given your ability to grapple multiple people at a time. Drag Ďem all into the hazards! Get enlarged (via a spellcasting ally or Potion of Growth) to shove/grapple the Huge foes, too!
- While the Simic Hybrid is by default a Ravnica race, it fits easily enough into other settings as some variety of mutant or other. For example they make a decent stand-in for the Half-Daelkyr race from previous editions of Eberron.
- Commanderís Strike is very much party composition dependent. If you donít have someone who would be a prime beneficiary in your party (such as a Rogue that wants an off-turn sneak attack), then switch it out for a different maneuver.
- You can mix up the order you take the classes to taste; just make sure you donít delay your Extra Attack. An example would be Barb 6 > Rogue 1 > Fighter 3 > Barb 16, especially if rolled stats allowed you to start with 18 or 19 Strength (after racial adjustments).
- If you have the rolls for it, itís possible to get an exceptional AC as a Barbarian via having 20 Dex and Con.
- Alert is an alternative to Lucky. With +7 Initiative and Advantage, youíre all but guaranteed to go first. Lucky is a bit more versatile, and you can still negate surprise using Rage / Feral Instinct.
- Simic Hybrids also make good Zealots. Probably merits a separate build post.
- If you've got extra space for a feat (such as due to rolling stats, or just looking to change up the build) Mobile is a good choice. The Mobile feat will allow you to Reckless Attack someone then run away, leaving behind only your allies who are even worse targets than you. Mind, you can do this with shoving or maneuvers, too.
- You can use this with GWM instead of sword and board, too. You'd have to sacrifice an ASI (which means taking it late or delaying maxing your Strength unless you rolled stats) and a shield, but it'll boost your peak nova damage vs AC 19 from 86.9 DPR to 112.3 DPR (plus possibility of Vengeful Ancestors). However note that you're less likely to activate Vengeful Ancestors if you're a better target, it won't help your ranged attacks, and using your natural attack -> grapple combo will cut into your DPR more, and if you've got a Rogue or the like in the party you can just use Commander's Strike instead (which as the Anydice link shows, lets the SnB build match the GWM build's nova).
Edit: Corrected for a mistake helpfully pointed out by Zene and Zigludo!
Edit2: Some relevant notes on grappling:
Spoiler: Some Notes on Grappling
Originally Posted by LudicSavant