While the concept of having a system, getting transmigrated as Riser, and getting the usual boons are generic. We can simply overlook that if we look on the bright side, the author at least executed it nicely (personal view) which makes the fanfic a bit more promising. Also the mc is a bit unhinged and less restricted compared to the original riser, don't forget a bit brainrotted, hypocritical millennial (definitely didn't quote the synopsis)
Writing quality, not that amazing but not that bad as well, just in the middle which is good. Some grammar mistakes or typos here and there that isn't much of a problem and won't ruin the immersion while reading.
The story is developing quite decently from how it's been going on, pacing is nice as well so no worries about it (might change in the future, currently 6 chapters available right now). Additionally, personally, I like this type of riser (the irony and hypocrisy inside me is boiling at this part of my message).
world background is dxd, as long as you know the anime, manga, ln, you're good to go. No need to worry about it, though you might also need to know a bit of a few others like jjk, waifu catalogue or CYOA stuff. Once again as, as long as you know them, you're good.
Overall, I really can't judge much since there's so few chapters at the moment (6 as of this review) but I prevailed and made one for the sake of another chapter. Back to topic, writing quality is good, pacing is good as well, plot is going well, as well as that kind of 'plot' 🍋. Though I wonder how'll you expand the story in the future, will mc have ten shadows or get mahoraga/get his adaptation (and also the ring above mahoragas head as a armament as it'd also look cool to have it). All in all, it's great, I've tried nitpicking on what I can get from the chapters but this is all I could get. I can recommend giving this a read.
Take this review with a grain of salt, it's based on my standards, liking, bias, and others to tell this. Give it a read to check if it suits your taste, cause it sure does to me.