The Royal Executioner (Reader Insert) (Undertale)

Many of you have heard of The Royal Judge, Sans. But, have you heard of The Royal Executioner? His name is Y/N, and he is The Royal Executioner of The Underground. He thought his job was pretty boring since nobody ever fell into The Underground anymore. However, little did he know that his life would change forever when someone with the soul of Determination came into The Underground & started slaughtering everyone. Even Sans fell to their hands. Now, all that's left between them & the total destruction of monster-kind, is The Royal Executioner, Y/N. Can Y/N stand against someone who can't even stay dead? Can he save all of monster-kind from this Genocidal path? If there's one thing that he knows better than anyone else, even Sans, it's that Determination is deadliest Soul known to exist. He has sworn to fight, To His Final Breath, no matter what would befall him. Little did he know though, Chara was still watching over him. . . Now, a question he must ask himself; How long will he have to wait for a pacifist route, or will it come sooner than he thinks? And what will it cost for the freedom of all monsters, to destroy The Barrier once and for all?