[Tactics]

I do not understand benefits Kadokawa got from this deal more than marketing to US through ANN reviewers.

I can see ANN agreed to this because they need an overlord to keep themselves relevant in current flow of information. Not expecting some kind of groundbreaking move from Kadokawa side, they've always been known for 'minimum expense for maximum profits', its not like there's any change to that considering their army of isekai and CGDCT titles so far.