The matter of if this is on the correct forum or not aside....
Sans probably can't, Round 1. For all his speed & powers, dodging fast & on the fly is what many members of AoT's military excel at AND Sans is a glass cannon; The upper limit on his teleportation probably isn't high enough to dodge quakes, shockwaves or Bertholt exploding. ESPECIALLY if he doesn't know a quake, shockwave or explosion is coming.
All the dodging in the world won't help if you can't get out of the range of an Area of Effect or Omnidirectional Attack that one-hit-kills you.
In future rounds, I'd think it's a little more ambiguous:
With prep, he might know to target the titan users, but his barrages of attacks & the deaths might be a bit conspicuous. Even if he has the sense to try & teleport in in the death of night, go all out, then kill & leave, characters in groups will have to be taken out all at once or he'll be noticed.
Once he, or a death is noticed, there's going to be a military after him. ESPECIALLY if he kills a titan user, since many people will realize that's extraordinary & not something you just do easily without being noticed.
If he tries to go after the infrastructure, that's guards & military taking notice AND titans noticing him.
& either way, he has to mind his stamina, & without teleporting, probably lacks good travel speed, meaning he'll have to take downtime between kills, leading to more time for investigation & outing him, & getting food without attracting attention won't be easy.
