Malenia, Blade of Miquella

Malenia may target creatures as if they were players
during combat.
Whenever Malenia deals damage to a creature, put
that many Scarlet Rot counters on that creature.
When that creature has Rot counters on it equal to
or greater than its toughness, its owner sacrifices it.
{5}{w}{w}: Prevent the next X damage that would be
dealt to Malenia, where X is the number of Scarlet
Rot counters on all creatures.