Blood Tithe Monolith

Whenever your life total changes, put a
+1/+1 counter on target creature you control.
{x}{4}: Pay X life points. Each other player
loses life equal to to twice that amount,
rounded down, as long as their life total
remains above 1.
{10} Monolith's Final Feast: Destroy All Permanents, lose half your life, keep 5 lands,
and end your turn.