You can only use 1 of the following effects of this card’s name per turn, and only once that turn.
(1) If you control only Reptile monsters while this card is in your hand: You can target 1 face-up monster your opponent controls; change that target’s ATK to 0, and if you do, Special Summon this card, then take damage equal to that monster’s original ATK.
(2) If this card is sent to the GY as a Synchro Material: You can target up to 2 face-up monsters on the field; change those targets’ ATK to 0.
Atom 1.0
