Bloomy is my fanmade antagonist for Chapter X of my fangame Deltarune: Chapter XYZ of Deltarune by Toby Fox.

In Chapter X of Deltarune: Chapter XYZ, The Roaring Knight seems to be the primary antagonist at first, but Bloomy yeets them out of the area. Bloomy then explains that he needs help finding the 5 souls (Black, White, Red, Cyan, and Brown) to "restore the Dark World back to it's true form."

SPOILERS FOR DELTARUNE: CHAPTER XYZ AHEAD!

Bloomy is later revealed to be what is called a "Chiaroner," meaning he stays the same in the light and dark worlds, and he can cross over at any time. Bloomy is one- if not- the only Chiaroner known to exist.

Bloomy's origins are unknown, but he keeps mentioning throughout Chapter X: "In my past life, I was almost a god."

While Kris, Susie, and Ralsei look for the other souls, Rielgore is also on the search for the other souls. While neither party knows it yet, they are unintentionally helping Bloomy become a god and destroy the Dark World. Rielgore ends up collecting the Black and White souls first.

In the end of Chapter X, Bloomy gets angry at Kris, steals the red soul, and transforms into Omega Bloomy. After Kris defeats Omega Bloomy, they get the red soul back. Rielgore then steals the Red and Kris's (Cyan) souls and uses all of the 10 souls to convert into his final form.