Myra, Watershaper

Eminence - Whenever a merfolk you control attacks, if Myra, Watershaper is in the command zone or on the battlefield, create X 1/1 blue Elemental creature tokens tapped and attacking, where X is the number of attacking merfolk, rounded up. Exile those tokens at the beginning of your next upkeep.
{4}{u}: Elementals and Merfolk you control get +1/+1 until end of turn. You cannot activate this ability during combat.