SPOILERS!!!
So, I skimmed the web novel of this recently and I'm hoping they veer into a different direction in the future, cause, IIRC, from here he kinda explodes into super OP territory really quick. Also the harem for the most part disappoints. On one hand he'll get a dragon girl and bang the elf's mom and sisters, on the other hand all the interesting monster girls, furries, and scalies basically get dropped for the most human looking races. Zamir and Jagira? basically dropped completely (hell I'm pretty sure the MC and Zamir have a conversation about her joining the harem and she's only slightly hesitant about it, and then she only shows up like one more time after that briefly.) And to top it off he randomly gets 10 extra haremmetes at once who are all the standard "humans with animal ears and tails"
After they retake the elf's kingdom it basically just goes into the MC working with magic to recreate technology from his world before we have an abrupt "Yeah I'm done, 200 year timeskip, all plot dropped"