Sanctuary: Safe Haven - Chapter 372: Vice Clan Master

Fate, a gatekeeper who had been working for the castle, is beset by a few burdens.

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

Kujo Yuuri, who had been playing Elysia Online, finally changed her occupation to the sage of her desire. Then, she was asked whether to go to the true Elyasia or not and selected [Yes], and somehow went to another world. Furthermore, she became a small child.

The small sage Yuuri and her companions’ love and adventure fantasy.

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.