Adrianix1234
I quite like this fanfic so yes please. If you want to make it more interesting you can make a trickster going through universes without his harem every now and then. You could also probably make to where in his mini universe time is essentially frozen while he goes off by himself to interact with the main plot and act weaker than he is.
the original idea of the curse at the start is a good way if you want to nerf him without being annoying just make him in an existential crisis about getting anything easily and end up having a resolution to strive by himself and only use that creative skill when absolutely necessary. and he discussed with his harem or they(his harem) focused on searching for knowledge this way, you can still continue the story without him being op destroying the story he would be using normal or even ingenious way to solve the problems ahead instead of directly creating skill to solve it there's a lot of creativity that can be put here
il say it again you don't need to nerf him you could take the wait and see approach and only intervene when necessary tho making MC Issei was a bit dumb and I can thus understand why you want to nerf. my suggestion would be that HP's magic just doesn't work in that world and since host took Issei and his body his strength is at most at the mid class meaning 2or 3 sets of wings meaning enemy's like kokabiel would still slightly be a challenge but kids his own age wouldnt
it look good at everything and his power but part clone make it's destroy everything some left or drop maybe some stay like me because we already veteran after all in reading everyone is fine about clone but when that's clone once meet his harem it's already destroy the story . Don't worry thought you still have reader like me or veteran one