This is a lot more interesting than most of the isekai slop we're served these days, but one thing bugs me. The demons are a potentially existential level threat to humanity, but why is the cardinal(?) withholding information for no reason, from the one guy that can help?
"I know everything but ain't gonna tell you jack, nerd. Figure it out lol."
Any LN readers found an explanation for this? Is he just a secret asshole?