Sorry to MC and Red for stealing their boxes, but I needed the space. For WORLDBUILDING!!!!

So, my initial thoughts was that I feel V would be a good choice for Sans, because she survives and has the Dingo, but that doesn't actually make too much sense.
Anyways, this would make N Papyrus, which I feel is perfect.
With this initial thought, Cyn as Chara, and probably Uzi as Frisk/Player.

anyways, then I found a bunch of MD x Undertale tracks. There was a few dusttale? (i think it was dusttale) x MD remixes, but I wanted base UT.

Anyways, the first one makes V Undyne. She would be a good choice, again, as she seemingly dies.
Second is N as Sans. I feel that this could work, as does Red (goldenmonkeypower for new folks).
Third is N with bonetrousle elements, making him Papyrus (again, mentioned above).
4th is just a silly Spamton Uzi.

Now it gets interesting. Everything from this point on is from CrazyDoofus, creator of the recent Bite Me Megalovania (YT comment said it should be called Megabyte/Megabite as a pun).
While they're on soundcloud, they're also on YT, with interesting comments on YT.

no comments of note on Core
Bergentrucking had: "DRIVING IN THE BUS, RIGHT AFTER A CAN 🗣🗣🔥🔥" -Khan just about to hit J in the epsiode 7"; i do feel that Khan is a good choice for Asgore. Both leaders

You Freaking Idiot was interesting. A comment (paraphrased): Uzi passed out from overheat, missing N, whom ran away, V dead, missed because she listened despite being annoying. Cyn/Solver shows up, and because Uzi wants a happily ever after with N, winds up losing control to the Solver.
But the creator's comment has Tessa as Frisk, and Solver as Flowey.
So Cyn/Solver as Flowey. Potentialyl Tessa as Frisk, but Red thinks (and I agree) that unnamed worker drone with the solver is better choice.

Eldritch Amalgamation is J's solver backup form thing as Amalgamate. We think this would work, but Red suggested this form as Photoshop Flowey.

Power of "Absolute Solver" has the Red Solver, indicating doll. "❤️ REASON; *You attempt to reason with Doll and tell her that she doesn't need revenge; *…; *She doesn't understand text box."
So Doll as MTT, although Red says they'd moreso be the robot from UT Yellow.

Penultimately, Megalovania Required. A comment (paraphrased) says: A solver controlled Uzi has killed V, J, Tessa, everyone N cared about. But N takes a nervous stand. Solver wears him down, bringing V back as the eldritch thing, but then N snaps as she comes in for the kill, overcomming his programming to fight at his lowest.
So again, N as Sans. And in the following comment from the creator, two versions now exist in their head, one with Tessa as Frisk, the other with Uzi as Frisk.

Ran out of characters for once, that was wierd....

anyways, Finally, The Bite Me Megalovania. Whoo boy.
"*you felt Cyn crawlings on your back"
"You are gonna have a bad ti-
YOU ARE GONNA GET SNUCK UPON"
"*You died, silly : )"
"Sans ❌
Cyans ✅"

So with this, Cyn as Sans? I feel that like how Megalovania is disconnected from the rest of the OST, and thus is speculated to be YOUR THEME, not Sans, that again, Solver is Chara (cause she takes over Uzi at one point), Cyn as Flowey (normal robot maid ver), TessaCyn/Cynessa as Asriel/God of Hyperdeath, and Uzi/Worker Drone as the player.

Which leads me to my final speculations!

Uzi as sans works really well cause the solver can be used for Sans blue attacks, throwing you around.
Again, I like V as Sans. And Red says V as Sans would work for a Underfell AU of Murdertale.
And N also works, as seen from comment on CrazyDoofus' first MD megalovania.

I remember the song