Sans: OHSHOOT! NONONONONONONONO!!!! *Sans starts to fall into the portal, face-first*

Cuphead: *He trips Rocky, making her fall in* Pfft! Karma's a bitch. Anyway... *He jumps in cannonball style* 

Bendy: Uh... Guess we gotta go through. *He puts Honeyfrost on his head, and jumps in*

Error: *He picks up Flowey* Okay, I guess. *He hesitantly walks into the portal*

Frisk: *Their eyes light up with excitement, and they dive in* WOOHOO!!!!

Chara: *She shrugs, walks to the portal, spreading her arms out, and falling into it*

Mugman: Cool! *He goes over to the portal and jumps in*

Boris: Okay! *He follows the rest*