Team Player

You enjoy succeeding, but you enjoy your fellow teammates succeeding just as much, if not more. 

If a team member fails an attack roll, saving throw, or ability check within 30 feet of you, you can use your reaction to bolster their resolve and allow them to roll an extra die in order to succeed.

You can use this feature up to a maximum of your charisma modifier (minimum of 1), and you gain all uses back on a long rest.