Junko, Despair Incarnate

Whenever a creature dies, its controller gets a
despair counter.
Whenever another player gets one or more
despair counters, you get that many despair
counters.
At the beginning of each player's precombat
main phase, that player may remove all of their
despair counters. If they do, they lose 2 life for
each despair counter removed this way. If they
do not, they lose 1 life for each despair counter
they have.