In Shin Megami Tensei: Nocturne's "Vortex" prototype, character models for Maya Amano (from Persona 2: Eternal Punishment), Lisa Silverman (from Persona 2: Innocent Sin), Sid Davis (Devil Summoner), and Lucifer's design from Shin Megami Tensei II are present. In the final product, the first three characters are absent and Lucifer appears in two different designs.

Additionally, Lilith seems to have had an important role in the prototype, opening up a path for the protagonist. In the final cut, this doesn't happen and she is merely a normal enemy demon.