Acyros, Precise Sharpshooter

Gunners you control have "{t}: This creature deals 1 damage to another target creature."
Whenever a Gunner you control deals damage to
a creature, that creature gets -1/-0 until end of turn and its controller loses 1 life.
{4}: Change the text of target Gunner by replacing all instances of "1" to "2" until end of turn.