Siren's Call [Alpha Edition] SM49 While this card is on

While this card is on the field

If this card has "Number 105: Battlin' Boxer Star Cestus" as an Xyz Material

killing and recruitment are one and the same

you may search your library for a creature card with mana value 1 or less

Siren's Call [Alpha Edition] SM49 While this card is onSet: Alpha 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.