Thunder Dragon + 1 Thunder monster
Must be either Fusion Summoned, or Special Summoned during the turn a Thunder monster s effect was activated in the hand, by Tributing 1 Thunder Effect non-Fusion Monster (in which case you do not use Polymerization ). Cards cannot be added from the Main Deck to your opponent s hand except by drawing them. If this card would be destroyed by battle or card effect, you can banish 1 Thunder monster from your GY instead.