Going back to the "Sans is a time and space traveler" theory, while I believe that the stuff leaking out of Sans in the Genocide run is ketchup, you can make a stretch and say it's because he is from the deltarune Universe where Monsters do in fact, maybe, bleed. After all, it's still up to debate and headcanon if it's blood or ketchup
Yeah, it could go either way for me at least in terms of the UT universe.
Although honestly, I don’t think the Sans from DR is the same as the one from UT, or is aware of it. I do think that everyone in the DR universe is separate from everyone in the UT universe.















