“不遇職【鑑定士】が実は最強だった〜奈落で鍛えた鑑定スキルが、チート化して全てを見切る神眼になった件” is just a former title of the web novel. The light novel title is “不遇職【鑑定士】が実は最強だった ～奈落で鍛えた最強の【神眼】で無双する～” and the series title is given simply as “不遇職【鑑定士】が実は最強だった”.
The English title as on the cover is “The Unfavorable Job [Appraiser] Was Actually the Strongest”
“異世界帰りの勇者が現代最強！ ～異能バトル系美少女をビシバシ調教することに！？～” is only the volume 1 title; the series title is simply “異世界帰りの勇者が現代最強！”. Not sure why you’ve translated it into Korean as this is definitely a Japanese novel?
I have both of the volumes (I think mainly due to the Arifureta artist) — the second one was released in 2018 but I’ve no idea if it is actually finished. The manga is still ongoing.
I love villainess stories and it's interesting that her power gets nerfed, I haven't read a lot of LNs where the MC's power goes down after being sent to their second life
Even if we assume that the average lifespan in their other world is 50 years, that would be 500 billion years. That’s thirty-six times the age of the universe.
How the hell could he retain memories of all that and stay sane?
