Geno Sans's jacket and slipper are completely white, and since he's from a Genocide timeline, he has a huge bloody gash that Sans gets after he's defeated in the Genocide Route. However, he has some differences to every other Sans.

Like the original Sans, Geno Sans has an unzipped hoodie jacket with a shirt underneath, along with short pants and fluffy slippers. When Sans brings Papyrus with him on his visit to the SAVE screen, Geno is furious. He is also very sensitive about Papyrus and will not let anyone touch his scarf. He blames both ] and Somebody fix this] for the genocide runs and calls them 'his murderer'. he is desperate to convince the current Sand to follow his plan, even if he has to use force. Geno is very manipulative and will continue to manipulate ] to gain his trust after erasing his mind. Geno Sans has a bloody slash on his white shirt from his fight against ] Geno Sans' right eye is covered by a glitch he creates to hide the right half of his head, which has melted because of his determination. Geno Sans has Papyrus' scarf around his neck he is very protective of it as if it is Papyrus himself However, he can travel to the anti-voids without risking death. Geno lives in the Save Screen with Frisk and, if he leaves it, time would continue for him and he would turn to dust.

Geno 'survived' the Genocide timeline by injecting himself with determination and saving as he died, sending him to the save screen, held in a state between life and death. Recently, he stopped doing this so that the current Sans will remember all the resets and Genocide routes in the previous timelines in hopes to get him on his side. If they don't agree, then he will erase their minds and starts over again. Geno wants to completely destroy the timelines, but as he only has a fraction of a soul, he tries to get other Sans' to do it. He lives in the save screen with the original Frisk. Geno is a Sans who was near-death in a Genocide timeline.

It also happens after the Genocide Route after you kill Sans. He is a main supporting role on Somebody fix this], which is now complete. He is now able to retain memories of prior timelines for the other Sans' to use, though he himself is stuck in the void. Geno!Sans is a version of from another timeline who injected himself with determination from Alphys' True Lab in an attempt to hijack the resets.

Death reaper sans