Jaguar's Island, Challenge Stage

[Barrier] [Permanent] This card can't attack. [Auto] When you activate a red "Earthling" Extra from your hand, add 1 marker to this card. [-3] [Activate:Main/Battler] If your Leader is a red "Krillin" card and you place 4 red "Earthling: Extra from your Drop at the bottom of their owner's deck : The next time you activate an [Activate] skill on a red Extra from your hand during this turn, reduce the skill cost by 1.