Team Leader (5e Subclass)
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Beginning when you choose this subclass at 3rd level, Whenever you see an ally make an attack roll you can say some words of encouragement and use a reaction in order to grant them advantage.
Starting at 7th level, on your allies turn you can use your reaction to grant them the effects of one of your usable abilities, this uses one of your charges of the ability.
Additional Fighting Style
At 10th level, you can choose a second option from the Fighting Style class feature all alies are also granted the effects of this fighting style while within 30 feet of you.
Starting at 15th level, whenever you or a friendly creature within 30 feet of you must make an attack or damage roll, the creature gains a bonus to the attack and damage rolls equal to your Charisma modifier (with a minimum bonus of +1). You must be conscious to grant this bonus.
At 18th level, you attain the pinnacle of resilience in battle. At the start of each of your turns, you regain hit points equal to 5 + your Constitution modifier if you have no more than half of your hit points left. You don't gain this benefit if you have 0 hit points.