Mae is the Revisetale version of Undyne.
Mae is very passionate in everything she does, acts quickly and is steadfast on her beliefs. Though she wants to defeat the protagonist, she tries to play fair and explain how blue mode works. Grillby taught her the values of pacifism, which is why she states the protagonist is "a wimpy loser with a big heart". When first encountered, she wants to take the protagonists soul and break the barrier, but if she is shown mercy, she's quick to defend the protagonist from Grillby. She loves to help others, and mentors Red. She is also sarcastic and cynical. She likes to watch anime with her friend, and was told it's human history, so she regards human history as exciting and cool. She has a lot of Determination, and when she's dying, she begins to melt, as she has lost sync with her Determination.
She has white bones and no hair. She has several scars over her right eye socket. Her pupils are white circles. Her fingers levitate over her actual hand.
During the pursuits and her battle, she wears a slightly purple hued suit of armour, purple boots and purple fingerless gloves. Prior to her battle, she also wears a helmet. After her battle, and during her hangout, she wears a black T-shirt, jeans and red boots. During her "Menacing" battle, she wears purple-hued armour with spiked shoulder pads, purple boots and purple fingerless gloves. There is a heart on her chest, and a bone is coming through her right eye.