@Hollow7F
Nah you have those fragments of the Demon Lord or whatever that exist. She's already fought the one which was infantile without form. Seems like the larger the pieces are, the more human-like it becomes. So this Bakko guy is clearly one of them, and if he's insisting Angie is like him, then that makes her another part. Who knows what the deal was with the beast that Belgrieve fought prior, perhaps someone who was consumed by the demon lord influence?
It seems like the hint we got this chapter is that the elves had something to do with suppressing the demonic influence on Angie. Which is why that healing item 'saved' her from that shadow thing in her dream and why she became all nostalgic. Remember she was delivered to Belgrieve from the forests, likely an Elf had seen his battle that cost him his leg, believing that Belgrieve was the only person capable of protecting and raising something like Angie. Or perhaps his meeting of Angie was a complete coincidence, but boy, in that case the Elves got extremely lucky.
I'm guessing the thought process is that if you can shape a majority of the demon lord fragments into a human with a consciousness like Angie, then when you gather all the fragments, her will should stay in control and prevent the return of the former-Demon King. It's probably a pipe dream they came up with since there was no other way to handle it. I mean if the demon lord is entirely indestructible and just keeps reviving... what the fuck do you do.