Ut, A Dusty Steamed Bun Under Pressure?

[Undertale AU fanfic + original headcanon + no romance + doomed from the start + vows to achieve the perfect ending] I transmigrated, but forgot my own name, and was badly wounded before getting stabbed for no reason. After narrowly managing to fight back and kill my attacker, Sans started wondering what to do with the body. In the end, he could only sigh that the sky was falling. What kind of game character can't even beat a kid? Should I just jump down and start over? As luck would have it, another kid who looked exactly the same saw the whole thing. Sans's face went blank as he considered the odds of being chopped up like spare ribs. My name is Frisk. For some reason, I ran into “Sans,” a guy who looks exactly like my friend. But his eyes are so strange, and the atmosphere in this hallway feels wrong... Is that guy a murderer? In desperation, I told him he was my friend, and he actually believed me? (The synopsis doesn't do it justice. Please read the story.)