Ok here are some characters I'll put before I start writing the story.

Classic( UT )

Fell ( UF)

Blue ( US )

Cross ( XT )

Dust ( DT )

Nightmare ( DreamTale )

Dream ( DreamTale )

Ink ( Multiverse )

Error ( Multiverse )

Killer ( KT )

Horror ( HT )

Razz ( SF )

Geno ( AT )

Reaper ( RT )

G sans ( ET )

Ganz ( GZTale )

King sans ( Story shift)

Fresh

Alter ( Storyspin)

Outer ( OT )

Epic ( Epictale )

Bird sans ( BT )

Sci ( sans younger version of him )

( Is it okay if I add my au dragon sans in there? If not,that's ok)

(By the way the book cover isn't mine except the book itself)