Undine’s Spring

Undine's Spring is the place where the slimes have made their domain, as well as acts as the home of the third spirit, Undine, and the birthplace of the Heavenly Knight Erubetie.

Luka fights a group of slimes, starting with Jelly Girl, then Blob Girl, then the Slime Sisters, only to be met by Erubetie after he is found "invading their home". Erubetie proceeds to attack Luka and almost kill him, only to be intervened by Undine. After Undine tests Luka, Undine joins Luka's party as the third spirit in his inventory.