Botsuraku Youtei Nanode Kajishokunin wo Mezasu - Chapter 3-3

Three years ago, Yun Qing Yan fell into the Immortal Realm from the mortal realm. Three thousand years later, he became Divine Emperor Yun who shook the entire Immoral Realm. Breaking through the void and returning back to the mortal realm, Yun Qing Yan discovered that only three years’ time had passed here. “In the past, I did not possess the power to protect the people I hold dear. Now, I want the entire world to grovel at my feet.”

- Description from Novelupdates

SSR-ranked killer Mu Hui died in an explosion, only waking up to find herself transmigrated into the body of a vicious female supporting character in a book.

Kubei was just an ordinary pencil and button pusher working a day job, hating his boss and making horrible speeches when one day he fell asleep after pushing an all-nighter. When he woke up, he was bound to a chair, facing three creepy robed women and in a body way too young and way too weak to be his own. As he slowly came to, he realized that he was no longer in the same universe as he was before. He had teleported to the Kingdom of Helius, where an all-powerful church rules its lands and wages war against the elusive group known only as Mages. Armed with an incredibly cocky neural interface that just won’t shut up and his own sheer wit, our MC will find himself not just fighting to survive, but maybe even something bigger than himself.