Heltholos, Towering Surfacer

Trample, Shroud
Heltholos, Towering Surfacer costs {1} less to cast for every 2 islands you control.
Whenever Heltholos, Towering Surfacer attacks, you may pay {3}{u}{u}. If you do, Heltholos, Towering Surfacer deals 5 damage to a defending player.