Tyrannocyte

Tyrannocyte can't be countered. Tyrannocyte
deals 2 damage to each opponent and each
creature and planeswalker they control.
An opponent may sacrifice a creature with
converted manacost X or higher, where X is
the total amount of creature and planeswalker
cards that that player controls. If he or she does,
Tyrannocyte deals no damage to that opponent
and creatures and planeswalkers he or she
controls instead.