Still no romhack/fangame that takes place some time after hgss, where a former Team Rocket member disguises himself and tricks Ethan/Lyra to call upon Celebi in Ilex Forest. He than uses Celebi to travel back in time to prevent you to from defeating Team Rocket in the first place. And than travel to different places and regions in pokemon history to stops the protagonists from defeating the villains and the legendaries.