Mahalia, Harsh Adjudicator

Flying, vigilance, deathtouch
Whenever a source an opponent controls deals damage to a creature or player, put a judgment counter on that player.
At the beginning of your upkeep, each opponent loses life equal to the number of judgment counters on them. You gain life equal to life lost this way. Players lose half of their Judgment counters, rounded up when Mahalia, Harsh adjudicator leaves the battlefield.