Dulcea, Wave's Lullaby

{x}{u}{b}: X target creatures attack this turn if able.
Whenever a creature attacks you or a planeswalker you control, put a verse counter on Dulcea, Wave's Lullaby. When she has 10 or more verse counters, exile her then return her to the battlefield transformed.
A siren sings not because it has a song, but because the song demands oblation.