Stalwart

You can go on fighting when others would collapse and
give up. You have advantage on saving throws against being
exhausted or stunned.
In addition, when you are stunned or exhausted, you can
try to shake it off. You can use a bonus action to reduce
your exhaustion level by 1. Alternately, at the end of your
turn, you can make a new saving throw against any effect
that has imposed the stunned condition on you, ending that
condition on a success (the save DC is equal to that of the
effect that stunned you, or DC 10, whichever is higher). In
either case, once you use this ability, you must finish a short
or long rest before you can use it again.