Souls,Bones, and Love (Various AU's X reader)

You've heard about Frisk Dreemurr, Ambassador of Monsters, savoir of the Underground, but what you don't know is that he has a twin sister. Y/N Dreemurr, she's Frisk's twin, though she never traveled to the Underground with him the Dreemurr family accepted Frisk's twin with open arms. That was 10 years ago, now at the age of 21 Y/N runs her own little flower shop bookstore hybrid business. Sans Serif, a brilliant skeleton monster who hides behind a smile and laziness. Older brother to the Great Papyrus. He and his brother are also the Soulmates of Frisk's twin sister Y/N. He messes around with something he should've left alone and brings more versions of him and his brother, along with another version of the late human child of the Dreemurr family. Turns out that they're also Y/N's Soulmates. Chaos and hilarity ensues as they fight for the girl's heart and love.