Mercy

It's been four long years since Frisk saved Chara. Chara had tried to thank the child by helping them rid and keep away the Anti-Monster cult members, but it didn't seem enough. Frisk finds a way to thank them in return for not trying to kill anyone these past four years by giving them a gift they would never forget. ...

Storyshift (Charisk)

Just what you'd expect. Pardon my lack of knowledge about this AU. I just like the concept. Both Frisk and Chara are girls. Characters may use absolutely different words than you'd expect. I'm still a rookie. Just assume they are aged 16 and 18.