Dalis is a cute female devil who resides in a castle in the 7th floor of the Toushin Toshi labyrinth. She was imprisoned by the King Dragon until Custom rescued her by slaying the dragon and retrieving the Sphere of Light. She joins Custom at his request to save Poe from Seruji, another devil who has possessed him. Dalis is strongly attracted to cute girls, and she even possesses Custom for a while in order to have some "fun" with one. When Dalis confronts Seruji in Poe's mind, it is revealed that the two devils have an S&M relationship, with Dalis being submissive. Despite Dalis' pleas for her to come back to her, Seruji says she's bored with Dalis and wants to keep possessing Poe. Dalis then absorbs Seruji so that they'll always be together.
Dalis makes an appearance in Toushin Toshi III as a Devil who makes a contract with Rachel Mamaleera in order to free her lover from an apparent insanity that is possessing his mind.
Nakuto manages to cancel the contract using a contract canceler before the deal is finalized and thus, freeing Rachel.
For her failing her job, Dalis received a rather amusing punishment. Devil Seruji then enlists the help of Nakuto to free Dalis in exchange for information on his father.
It is likely that Toushin Toshi III takes place in a parallel world that is different from the previous Toushin Toshi games. Hence, the Dalis and Seruji that make an appearance in this game are parallel versions of their previous Toushin Toshi game selves.