If this card battles a monster, neither can be destroyed by that battle. You can only use each of the following effects of "Hecahands Gaigas" once per turn. If a card(s) is added to your opponent's hand (except during the Draw Phase or Damage Step): You can Special Summon this card from your hand. During your Main Phase: You can excavate the top 3 cards of your opponent's Deck, and if you do, you can Special Summon 1 excavated monster to your field, also shuffle the rest into the Deck.