Sans

Sans is in the role of Undertale Undyne. He has a lot of Determination, and pursues the protagonist throughout Waterfall. He is the head of the Royal Guard

Personality
Sans is passionate about everything he does, acts quickly and is steadfast on his beliefs. Though he wants to defeat the protagonist, he tries to play fair and explain how blue mode works. Alphys taught him the values of pacifism, which is why he states the protagonist is "a wimpy loser with a big heart". When first encountered, he wants to take the protagonists soul and break the barrier, but if he is shown mercy, he's quick to defend the protagonist from Alphys. He loves to help others, and mentors Scora and Catty. He is also sarcastic and cynical. He likes to watch anime with his brother, and was told it's human history, so he regards human history as exciting and cool. He has a lot of Determination, and when he's dying, he begins to melt, as he has lost sync with his Determination.

Appearance
He has white bones and no hair. His left pupil is blue and circular and he has no right pupil, but has scars over his right eye socket. During the Genocide fight against Sans the Sansational, his right pupil has a phantasmagoric bone coming through his right eye socket.

During his pursuits through Waterfall and his battle, he wears a suit of armour, which is shiny and silver. During the pursuits, he wears a helmet that matches his armour, blue gloves and blue boots. After his battle and during his hangout, he is wearing a white T-shirt, blue jeans and his blue boots. During the "Sans the Sansational" fight, he wears armour with spiked shoulderpads and armour similar to his Neutral fight, but with a blue heart on the chestplate.