Hotarubi

As beautiful as nature herself, Hotarubi summons her animal and insect minions to bring her adversary to their tragic end. In love with an happily engaged to Yashamaru, it seems he is her only weakness. Even her snake recognises friend from foe and isn't fooled when Saemon takes on her lover's identity. Because of her unwavering loyalty and love for Yashamaru, she clings onto any fragment of hope that her one true love is still alive. But once her heart is set on revenge, hell truly hath no fury like a woman scorn.

(Source: FUNimation's Official Basilisk Website)