Phantasm Emperor Trilojig (Common)

3 Level 10 monsters If this card is Special Summoned, or if another monster is Special Summoned from the GY to your field while you control this monster: You can target 1 face-up monster your opponent controls, inflict damage to your opponent equal to half its original ATK. You can only use this effect of "Phantasm Emperor Trilojig" once per turn.