Board Thread:General Discussion/@comment-37279050-20181023140303/@comment-37509773-20181114200411

So, my theory on Chara wanting Frisk's soul...

Chara wants Frisk's soul because they don't have one. when Chara died, Asriel absorbed their soul out of grief. When Asriel died, both of the souls were destroyed and flowey became a souless being. He tried multiple times to feel feelings by doing certain things, but was never able to. later in the pacifist route, when you reach the Omega Flowey fight, he expresses feelings of gratitude when Asgore is dead. he absorbed the souls and was able to feel things again.

Chara wants Frisk's soul to 1) have a soul 2) feel things 3) gain more power (of they already have a soul)

but you know, just a theory...