You can remove 2 A-Counters from anywhere on the field to Special Summon this card from your hand. Once per turn, you can place 1 A-Counter on each face-up monster your opponent controls. (If a monster with an A-Counter battles an "Alien" monster, it loses 300 ATK and DEF for each A-Counter during damage calculation only.) You can only control 1 "Alien Overlord".