Siren's Call [Beta Edition] Explorer it creates twice that many

it creates twice that many of those tokens instead

waiting for a victory only it can see

rounded up

If that mana is spent on an instant or sorcery spell

then sacrifices the rest

Siren's Call [Beta Edition] Explorer it creates twice that manySet: Beta Edition Type: Instant Rarity: Uncommon Cost: {U} Cast this spell only during an opponent's turn, before attackers are declared. Creatures the active player controls attack this turn if able. At the beginning of the next end step, destroy all non Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.