Sans, Papyrus, Edge, Fell, Stretch, and Blue. Underfell Papyrus is Edge, Underfell Sans is Fell, Underswap Papyrus is Stretch, and Underswap Sans is Blue. Girl name Creator teleports them in the room they start to freak out. Creator speaks though the speakers

Creator: Hello everyone you are here to do a reaction.

Fell: Who are we reacting to?

Creator: Serra…

Sans: We are reacting to that little murder.

Creator: She wasn’t like what she is now also you are reacting to her past and why she*