Context

So imagine SP Dusttale, but broader ((Since this was obviously inspired by it))

So ZT is his name now—hence the title "stolen ZTories"—and he's hellbent on killing quite literally everything, indifference is pretty much his only feeling. This doesn't only limit itself to Undertale, once his task is completed in one universe, he immediately moves over to the next closest one, rinse and repeat

Though a lot of the damage he inflicts upon his opponents are mental, slowly chipping away at their own willpower to fuel his own until ultimately wiping them out

In this scenario, he's wearing Asgore's armor / trident since he immediately charged towards the throne room and KO'd Asgore ((by, again, wearing down his mental state with memories of Toriel, the children he has killed, Asriel, and so on. ZT is uncannily smart, but a big weakness is physical violence once you wear down his agility)), wearing Asgore's armor as a sort of trophy to immediately wipe out any monster's hope of reaching the surface ((Also destroying the souls since ZT can't even use them)), ultimately giving ZT an opening to wipe out monsterkind.

ZT refuses to negotiate no matter what, often not speaking at all unless necessary.

His LV is probably super high already but it's hard to determine since data being transfered from one universe to a completely different one can be messy, so checking his stats only reads as:

ZT

ATK: 3 (99), DEF: 28 (99), LV: ??

One ability he does have thay proves more than useful is his Replicate ability, letting him use specific powers that he sees others use. The downside is that he has to study it for a large amount of time, so right now he can only replicate fire magic.

This was just a dumb idea I had but the story sounds pretty neat.