Sigma, Gravity Master

Double Strike, Ward {3}, Ultimate Charge
{u}{u}: You and up to 3 target creatures you
control have protection from any nonplayer
target until this ability is activated again.
{3}{u}: Counter target activated ability.
Gravitic Flux—{3}{u}{u}, {t}, remove 18 ultimate counters from Sigma, Gravity Master: Your opponents lose half their starting life, rounded up
and their creatures deal damage to themselves
equal to their power. Activate only as a
sorcery.