[ ...Prompto stops to consider this for a moment. He's never really questioned it before! He just sorta...went along with it. ]

I think it was kinda like...a "prove yourself worthy" sort of thing? Y'know. He had to earn his way in and then the ghost kings were like, "here's a super powerful axe, use it wisely". Just like in a video game!

[ But don't read too much into that. ]