Sans (Swap Sans)

As a Sans but with the personality of, US!Sans is kind, energetic and has a belief that everyone is a good person. This is broken after he's overwritten back to normal, and he fights X-Event!Chara even if Underswap!Chara is dying from it. He relies too much on his brother, so much that he wouldn't go without him, despite leaving Underswap when it was confirmed that he wouldn't come. In 0.4 however, he seemed to realize the problem much quicker, even going as far as to call out Ink's actions during his and Error's battle, possibly because of the experience and realization the episode prior. (this is a remake)