*They are... still alive? Whatever, just kill them already.

So, basically, Lin finally dies but the giant squid dog takes his place. Sans gets hit, heals himself with cursed energy (Yes, from jujutsu kaisen) and turns into the honored one. Noob acts with Gasters help and somehow summons The Dungeon Curse (from terraria) and Spongebob.

Motifs:
Undertale - Reunited
Changed - The finale
Undergarf - You're gonna have a bad monday 
Undertale: Hard-mode - At least at the end (by @KyphoXis )
Deepwoken - To Sleep, Dreaming
Terraria: Calamity mod - Curse of the Dungeon
Blocktales - Hatred
Robloxtale - Asteries
Undertale - Dark yet darker
Spongeswap - Bibulus
Changed - Squid dog boss
Undertale - STMPWYFS

Just Another Trio - Despair calls from the deep (Phase 2.5)

Marley Blackwood