Dust!UnDtale

not going to be that depressing since it's only 3 characters well if you can even include Phantom papyrus

Alternate Timeline

Story
Dust!Dtale!Sans was fighting the human as usual until he felt something was wrong with him so he went all out on the human so he could check what was going on. Then he realized his DT was fading away he tried to go to the lab but Frisk realize that some time ago so when Sans killed she/he he went to the lab and burnt it down when Sans got there he saw that now the rest of the DT is gone so when his DT faded away. He ran away. Meanwhile before Frisk burnt the lab down, she/he took 10 DT syringes to see if it will make her/him stronger so after Sans went to Hideaway Frisk injected the syringes but it was too much and it killed Frisk forever Sans lost Phantom Papyrus as well now only he remains and the Core ran out of power means no light

Information
This will not happen in Dtale!Dust as Sans took enough DT to last him for a very very very long long time probably like 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 years even if he did ran out Frisk will probably not know this so Sans could probably go and get some more well it depends if there was even DT syringes still there in the first place and even if it happened Frisk will not be that dumb to take DT syringes