Looking over this again.

I agree with the concern about increasing allies' AC, though I'm having trouble thinking of an alternative for Battle Meditation. Perhaps it actually gets nothing at all from the base class and is purely based on the archetype chosen, even--that might help expand the possible archetypes you'd like to do.

I also noticed that Extra Attack seems odd to grant a 3rd attack. It also generally seems like combat classes get an Attack improvement at 11th level (see Paladins and Rangers). Perhaps a Command option at 11th level like, "When you take the Attack action on your turn, you may (as a bonus action?) choose one ally within 30 feet that can hear and see you. That ally can use their reaction to make a melee attack." You can move the current 11th and 13th to 13th and 15th.

Unity does seem like a good name for the first archetype.

Quote Originally Posted by MoleMage View Post
I think you got the right spot on Arcane Connection. Being as it is at the end of the class it seemed fairly balanced to my eyes. It has everything an endcap should have: enough power to make the class enticing over multiclass, not so much power that the class is the only choice, and it feels cool.
I pretty much agree with this. It also drains some resources to do it, so I think it works. You might prefer to have it cost TPs based on how many creatures are affected by the ability, though, if it still seems too strong?

Overall, I think it's fairly close to something I'd consider using.