The Wormhole

As an additional cost to cast this spell, pay any amount of life and/or {e}.

Ward - Pay life equal to the number of Clamy tokens you control.

When the Wormhole enters, each opponent creates X 1/1 Clamy of the Future Past creature tokens, where X is half the amount of life and/or {e} paid to cast this spell.
Whenever a Clamy creature dies, its controller sacrifices a creature. If a Clamy creature is sacrificed this way, they lose 2 life, you lose 1 life and draw a card.