StoryNeil in underswap is just like his brother, Ash C. E. Granger, in normal Undertale. Neil constantly bothers his brother, Ash Granger/Underswap. Neil's name in Underswap is now Nega Neil, and will stop at nothing to destroy the world. However, if Frisk befriends him, he will stop being evil and become friends with them, similar to what Ash Evil does in normal Undertale.
Neil wears a blue hoodie, black jeans, and blue shoes. He has orange eyes, and his hair is now a bright, vibrant orange.
Neil will attack similar to Papyrus and Ash C. E. Granger, however he is less powerful than Ash and more powerful than Papyrus. He will not dodge, and if you are on a Genocide run, he will be as easy to kill as Papyrus in Genocide.