Wow this did not happen in the novel at all and im surprised they put it in here so early, the reveal happens so much later in the novel, I wonder how they’ll go about this in the future
Welp huge spoiler then
Elijah’s headache was something they added in the manga (I’ve read the novel three times unless I’m somehow illiterate or have memory issues it was not in the novel AT ALL)
He saw Arthur’s past life aka King Grey as a silhouette and those negative feelings towards him. They belonged to Nico, King Grey’s childhood best friend from their orphanage. Long story short because idk how detailed you want to be spoiled, Nico thought Grey had betrayed him when they were still on Earth, despised him with all his being, and next thing we know he was isseikai-ed into Elijah’s body(whether or not Elijah was born/made for the sake of this, sorry I’m not too sure on this part. But I would assume so), so now Nico/Elijah is enemies with Arthur/Grey.
The reason why I’m surprised because the isseikai thing happened so much later in the plot, like now if you only read the manga you have no idea who Nico is right? The flashbacks of mc’s past life haven’t even been shown yet. So if they decided to put this very obvious foreshadow so early, I can only imagine they want to speed things up A LOT.
Hope this clears things up.
Chant with me y’all: fuck ‘em up fuck ‘em up FUCK ‘EM UP FUCK ‘EM UP