ictoan's manga / #age gap(4)

This manga is based on a web novel that was completed in 2015(?). I love the time-travel theme, especially when it brings out the contrast of ability between Sage and Hisoku. One goes back in time while the other goes into the future to try to save each other. The Blue King lies in the present between the two. The translation group that's doing the manga is now also translating the novel so I hope to read the rest of the story soon!