Gawr Gura - samurai shark

"Back to the past. Back to the past. Samurai Shark. Watch out!"

Who would fit the role of Aku in this scenario best?

I've got Ame (Time Powers/Gremlin Laugh), Ina (Design has tentacles, Cunning as seen in her games of chess), Callie (Death Motif, Color Scheme), or Kiara ("Shapeshifting" abilities/am x videos, Bottom Left)