Desolation Sliver

Eldrazi you own that aren't in play, Eldrazi
creatures and Eldrazi spells you control are
Slivers in addition to their other types.
Slivers you control have devoid and annihilator 1.
{2}: Create a 1/1 colorless Eldrazi Sliver token
with "Sacrifice this creature: add {c}."