Leviathan

Fairy Leviathan, known in Japanese as "Yōshō" Leviathan (「妖将」レヴィアタン, 「Yōshō」Reviatan, Yōshō literally meaning Siren General), or simply Leviathan, is a member of the Four Guardians in the Mega Man Zero series. Leviathan was created from X's DNA data to aid humans resettling the Earth after the destruction of the Elf Wars. She is a military general of Neo Arcadia, commanding the Deep Sea Squadron (冥海軍団 Meikai Gundan, literally "Army of the Dark Oceans"). She wields a spear called Frost Javelin (フロストジャベリン Furosuto Jaberin). Like her siblings, Leviathan's armor is based on that of her biological origin, X, with thematic alterations. Her armor is colored blue, symbolizing her alignment with water and ice. Her helmet frames her face in such a manner as to resemble hair, with the sides forming the 'fringe' and a seashell motif forming the 'bangs'. The back is mounted with a long dorsal fin-like jet, which she uses to propel herself through bodies of water. She wields a harpoon-like Frost Javelin, the size of which she can alter, and she uses it to create ice and launch torpedoes. To highlight her femininity, Leviathan's torso armor resembles a female swimsuit, her gauntlets are long like opera gloves, and her boots have high heels. Fairy Leviathan is a playful, sadistic, and mischievous woman. She is easily bored, but takes pleasure in retiring Resistance soldiers to pass the time. She prefers to stay underwater, stating that land is "too dusty" for her. Like the other Four Guardians, she is deeply loyal to X and follows his every command.

Leviathan becomes obsessed with Zero as she fights him. She warns him not to hold back just because she's a woman, and is offended when he doesn't finish her off. She states that losing to Zero "drives her crazy". However, she also comes to enjoy that Zero is stronger than her, claiming she's been looking for a powerful Reploid to one day overcome. She also notes that fighting Omega isn't as fun as fighting Zero.