First Assistant's Petite Wife Has Space - Chapter 258 - Too much to Drink

Shu Yu transmigrated and became the original novel’s violent and brutal female Demon that caused the supporting male character, AKA hidden Boss, to become batsh*t crazy. However, right now, the Boss is just a lowly slave that was just given to her. What should she do?

- Description from Novelupdates

An old MMORPG called Live Dungeon. Before the service was terminated, Kyotani Tsutomu made full use of 5 notebook PCs to clear the game and was invited to a different world. And then, Tsutomu was speechless when he saw a live relay of a dungeon capture in the different world. They bulldozed through without any thought of strategy. The misfortune of getting the healer position. Tsutomu reinstated the White Mage that had always been his favorite in games and aimed to conquer the dungeon to find the key to his escape from the different world.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates