Self-Destructive Purge (Fighter class)

Substitute for Indomitable.

Once per long rest, as a bonus action, you can roll twice the amount of times you currently can for attack and damage rolls for your next single melee attack and add all numbers to their corresponding results, in exchange to receiving one level of exhaustion at the start of the next turn. You can activate this feat twice every long rest at level 13th, and thrice every long rest at level 17th.