Sirene in Neo Devilman

Sirene is a demon and one of the primary villains of the Devilman franchise. Most versions of the character have a history with the demon that fused with Akira Fudo and seeks to destroy him to get vengeance. Since her first appearance, Sirene has become one of the most iconic characters in the Devilman franchise, and has been featured in nearly every Devilman series to date, even starring in several spin-off manga.