You can only use 1 of the (1)st and (2)nd effect of this card’s name per turn, and only once that turn.
(1) You can send 1 “Regenesis” monster from your Deck to the GY, then target 1 face-up monster your opponent controls; change it to face-down Defense Position.
(2) During your opponent’s turn: You can send this face-up card from your Spell & Trap Zone to the GY; Special Summon as many “Regenesis” monsters with different names as possible from your hand, GY, and/or banishment, but send them to the GY during the End Phase.