Must either be Fusion Summoned, or Special Summoned by Tributing 1 non-Fusion Thunder Effect Monster during a turn that a Thunder monster’s effect was activated in the hand (in which case you do not use “Polymerization”).
(1) Your opponent cannot add cards from their Deck to their hand, except by drawing them.
(2) If this card would be destroyed by battle or card effect, you can banish 1 Thunder monster from your GY instead.
Atom 1.0
