Review Detail of FireFox2590 in Highschool DxD: A New Satan

I can't give this a great score, I was really enjoying it at first, got a few crossovers and references here and there, the character gets pretty OP super quick (I am a bit of a fan of a character who trounces their opponents), but lately its been getting worse in my opinion. For 1, we are on chapter 51 and we still haven't made it to the present day. 2, the crossovers have become super excessive, I think that the author has to have crossed over with at least 15 different universes by now. 3, there has very little action until very recently. 4, The main character has become stagnant for the most part with their powers as far as I can tell, we aren't learning about anything new they can do or seeing anything cool. 5, we HEAR about all kinds of stuff that other people are doing, training, learning new techniques, becoming cooler, but we don't get to SEE any of that and just have to take their word on it. 6, the main character hasn't gone up against anyone his equal that I can think of, he hasn't really had any challenges, he just waves his hand and people disappear essentially. Those are the things I can think of off the top of my head that I see as issues. Really I wish I could have kept reading, but the sheer number of crossovers just finally made me too uncomfortable to continue, it barely even feels like DxD anymore and it turned me off of the book.