The Promised Neverland - Vol. 14 Ch. 120 - Formless Monsters

[MangaDex]

 

[SpecialProjectY]

Nothing new if one read carefully, it was mentioned before when they visited Day and Night temple with Golden Waters in chapter 103...

Drawing with demons consuming other things and gaining their traits.

Also, Nous eating Nouma, he gained her memories and abilities.

Looks like the demons work like Iratus bug from Stargate Atlantis.

Norman plan might work but doubtful that the demons would gave up their "humanity" without a fight.