Discontinued (Undertale) Trapped Souls - Chara x Sans (R 16+)

Sans knew Chara Dreemurr long before Frisk fell and all the numerous RESETs - he just forgot all about it and someone wasn't happy about it. [Chara is female in this fic; Don't know if this fic should have trigger warnings but I'm putting it there anyways] (Also on Archive of our Own, under the same username: Fenrir...