Aiko

Aiko, being a succubus, can change her body proportions however she wishes, though she does  have "born proportions"

She isn't very strong physically, so she uses her power to seduce people into doing her dirty work.
so while she has never actually killed anyone, she has sent many men in her stead.

Her castle is filled with all men, save for 1 other female demon, she actually treasures Lani and keeps her close.
She will punish any of the men who try to harrass or bother her in anyway.