OKAY! So as I was getting my daily Catchy-Spinny for Pokémon Go as I've been getting for the past...(checks)...495 weeks?... Jegus... SO ANYWAY! As I was doing that I was FLASHBANGED with an idea for a Deltarune Au and had to drop everything to write it down and draw it. Jailbroken Tenna or, Time Traveler Tenna Au.

Any device you can think of has been made into a time machine in pop culture; cars, microwaves, cellphones, tape measures, pocket watches, gyroscopes, why not a CRT TV?

Premise: Tenna learns the truth about Spamton's benefactor waaay too late, but still makes it his mission to undoom them and keep himself from getting unplugged, y'know, go back to the good ol' days, fix everything (that certainly won't go wrong...right?). Even though he still sucks at using computers, he's TV, he knows video games and sci-fi movies inside and out and he figures out how to use the Deltarune UI. He manages to open a 4th save file and uses it to go back in time and stall Spamton long enough for his past self to catch up after picking up the phone. He then jumps back to the "present" (his previous file, file 3) and finds... that nothing changed. That's okay! He knows more now, he can fix it. He keeps jumping back and forth, each time making a new save file, trying to figure out what he's doing wrong.

He tries keeping himself from meeting Spamton

Acting in place of Mike

getting rid of the studio's phones

even replacing himself on one attempt

anything that could change something

He gets more frustrated with each failed attempt, but refuses to stop trying. NO, he'll MAKE IT WORK! He makes dozens if not hundred of attempts. The phone even rings again, ordering him to stop messing with the game because he's breaking it (he tells them to kiss his ass)! Not to mention, he doesn't have fans, this time travel business is overheating him... a lot. He completely ruins his old outfit.

In between each attempt he comes back to Castle Town in File 3 and talks to the people there, including Spamton. They talk and Tenna laments their current situation, insisting each new try will be the one where it works, but eventually... after they've talked enough, after they've reconciled and gotten comfortable together again, he gives up.

He can't get their former glory back, but he has what he wanted; people who care about him (including his partner), a purpose with the Lightners (he knows about MTT, he's just been... putting it off until he fixed this), and... he's here. He's still alive. Things might not be exactly how he wished, but that doesn't mean they're all that bad either. He doesn't "fix" the future, but he finally learns from the past, he grows from it.