GenoFight.Genofight is an undertale au where hundreds and hundreds of genocide runs have taken place. after so many genocide runs sans finally gets fed up with seeing everyone die in front of him. He starts to stalk frisk and realizes that every time that they die they come back at the last point the felt determination. He takes to the lab with the help of the unknowing doctor Alphys and researches their determination. sans found out that he could stop frisk once and for all by suppressing their determination using overflowing magic power to stop frisk from regenerating. sans knew the power of his judgement eye was the most powerful thing in the his universe. after this realization he searched for more of them. Finding the power in both undyne and papyrus. right before frisk kills them sans takes their eye of power. after gaining both eyes sans puts papyrus's eye in his right eye and undyne's in the middle of his forehead. sans then became so powerful he did not have to follow the rules of his coding and accidentally messed up frisk's codes. neither one had to follow the rules of their universe. frisk sensing a threat takes the power of the six human souls and goes to fight sans. with all the new power they both destroyed their universe and continued fighting on other plains of existence. due to the fighting and their home universe being destroyed sometimes they will flash in and out of existence. but they will always come back. they occasionally attract the attention of ink!sans and Error!sans. chara is even more blood thirsty and tries to destroy them all. causing a team up of the three. chara overpowered them and sans is still fighting chara and until the end of time.
Chara/Frisk: chara has consumed and taken complete control of frisk's soul. after knowing about the power of the six human souls takes the liberty of trying to destroy everything in their path. even Error!sans nearly killing him.
Sans: Has the power of undyne, papyrus, and himself resolves to defeat every chara in every universe. after so many resets sans eventually went a little crazy but not as bad as Horror!sans. he is good friends with underswap!papyrus.