Board Thread:General Discussion/@comment-27907368-20160506131212/@comment-26347196-20160513154526

Isthereaplace wrote: If we accept that Chara is the narrator, they stay with Frisk on the pacifist run, because there is narration after fighting Asriel. On neutral runs, or if Chara isn't the narrator, there is no clue what happens to them.

So, after a pacifist ending, either Flowey is left alone, probably with six human souls to play with, or Flowey and Chara, who isn't implied to have become a better person, are left behind, again, probably with the six human souls.

There goes your happy ending, better say goodbye. I don't know if Chara can use their determination or not, but I think according to Genocide Route, Chara's essence lies dormant can be slowly awakened as you go down the Genocide route. However, if you go to the True Pacifist route, it would mean their essence is not awakened at all.

Furthermore, you never know the whereabouts of the Six Souls at all. Maybe they vanish after breaking the barrier, maybe they stayed in the underground, maybe they are released to the outside world. However, given all monsters' souls are returned to their body (evidenced in their existence in the True Pacifist route), a possibly logical speculation would be that the human souls have returned to their respective body, which could work, given all human corpses are kept in the graves in New Home.