Adrenaline Rush

When an ally falls unconscious you can instead fill them with burst of last minute power, for one round. They heal 1d12+ spellcasting modifier they have advantage on all attacks & they're gain a critical hit on a 19 or 20 of the 20 sided dice roll. At the end of there next turn the target fall unconscious & receives one point of exhaustion.

When up cast the healing increases by 1d12 & the player stays conscious for a number of rounds equal to the slot level spent.