Warlock Otherworldly Patron: The Hero of Legend (PEACH)

[Lord Von Becker]

Okay, I like the ideas you've got here. I think I can help with the execution a bit, though. (Red text is changes, strikethrough is deletions. Apologies if I've overstepped; I can be overeager sometimes.)

Otherworldly Patron: The Hero of Legend

You have made your pact with one or more of the legendary figures of epic, history, or myth, who guides you to follow in their footsteps. Perhaps you are a descendant of this patron, or perhaps you contacted their spirit by occult means. Regardless, they have empowered you with a piece of the magic that the Bards have which has woven its way into their legend.

This is a bit of a nitpick, but Bards with a capital 'B' necessitates the widespread influence of that adventuring class.
(Incidentally, what about unsung heroes? That sounds like an interesting concept.)

Expanded spell list: The Hero of Legend lets you choose from an expanded list of spells when you learn a spell. The following spells are added to the Warlock spell list for you.

1st level	Bane, Heroism
2nd level	Aid, Enhance Ability
3rd level	Clairvoyance, Crusader's Mantle
4th level	Arcane Eye, Guardian of Faith
5th level	Legend Lore, Hallow

No redtext, since I was mostly just putting it into a table. (Edit: I was pretty happy with how it looked in the editor, but on display it looked bad. Sorry about that.)
Incidentally, should Spirit Guardians be on there somewhere?

Heroic Arms: At 1st level, you gain proficiency with medium armor, shields, and martial weapons.
When attacking with a weapon with which you have proficiency, you may use your Charisma modifier, instead of Strength or Dexterity, for the attack and damage rolls.

Looks reasonable. I assume it shares this with the Hexblade. (Heavy armor would be on-theme fluffwise, but probably broken - I should just write and post my armor fixes.)

Hero’s Guidance: Starting at 1st level, you may give a number of allies equal to your charisma modifier all allies within 20 feet of you 1d4 temporary hit points, and advantage on their next attack roll or saving throw, as a bonus action.<sentence break>
Once you use this feature, you cannot use it again until you finish either a short or a long rest.

Reasoning: It flows better, and as a once-per-rest thing, letting you buff up a small army if you have one probably isn't broken. If you're worried, though, I'd still swap CHA for Warlock level, to really drive home the 'improving as a commander' thing.

Legendary Resilience: Beginning at 6th level, whenever you or a friendly creature within 10 feet of you makes a saving throw, the creature gains a bonus to the saving throw equal to your Charisma modifier (with a minimum bonus of +1). You must be conscious to grant this bonus. [As the Paladin's Aura of Protection, with no 18th-level improvement]

Hmm. Balanced, with the caveat that stackable auras can break 5E wide open. Might rename it, though - it's clearly for protecting more than just yourself, and isn't a way to give you Legendary Saves.

Katabasis: At 10th level, you gain the power to contact your patron during a long rest. When you do so, you may converse with their spirit about anything they would know, including their history, the plane of their afterlife, and the traditions they inspired or exemplified.
A righteous warrior might tell you of wars and the heavens, a chaotic priest could speak of madness and miracles, and a tyrannical wizard-king could tell you of rulers, fell sorceries, and the Nine Hells.
If a subject is within your patron's purview but beyond their personal experience, specifics are difficult to obtain. These questions must be kept simple, and you can only ask a number equal to your Charisma modifier (minimum 1) in a single rest.

I wound up rewriting that wholesale. Not sure I should have. What do you think?

Crowned in Glory: By 14th level, your fame begins to rival those of the heroes you study. Once per long rest, you You may take a bonus action to gain the following benefits for 1 minute:
- You cannot be charmed or frightened, and you gain resistance to one damage type of your choice.
- You have advantage on your attack rolls, and your attack rolls are critical hits on a 19 or 20.
- When you reduce an enemy to 0 hit points, all enemies within 20 feet of you must make a Charisma save against your spell save DC, or be frightened for 1d4 rounds. Additionally, you and all allies within 20 feet of you gain temporary hit points equal to 1d10+your Charisma modifier.

Once you have used this feature, you can't use it again until you've finished a long rest.

Just some flow edits. I do wonder if it would be better to make the temp-HP automatic on activation, though.