Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 17 - 17-27. Authorities on Loan

The world’s worst offense, is called Love.

Su Wan is a Realm Destroyer. She shuttles to different time-spaces using the identity of the “Cannon Fodder Ex-Girlfriend”, dedicated to plotting how to happily tear apart the male protagonist and the female protagonist. –There’s no such thing as protagonists who can’t be torn apart, only Ex-Girlfriends who don’t work hard enough~

- Description from Novelupdates

As one of the first players to gain access to World of Falan—the first immersive game worldwide—Roland creates his character as a Mage.

However, playing as a Mage is not as fun and easy as he thought. His head even explodes after he casts the very first spell in the game.

Stubbornly sticking to his class when most Mages decide to create a new character, Roland gradually discovers tricks of the trade and his unusual talent. This allows him to change people’s stereotypes on Mages and to explore the deeply-buried secrets of this game…

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.