Quest for a Livid Soul

At the beginning of each end step, if a source an opponent controlled caused you to lose life this
turn, you may put a quest counter on this ordeal.
Every time a source an opponent controls causes
you to lose life, note how much life you've lost in
total(since this ordeal came into play).
Remove 6 quest counters from this ordeal, and sacrifice it: Until end of turn creatures you
control get +X/+0. X is the noted total.