MTL - Counter Attack - Chapter 29 Popularize certain aspects of knowledge

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

In the world of Norse mythology, a human boy falls in love with Waltraute, the fourth Valkyrie sister. He wishes to marry her, but Waltraute gives him an impossible challenge to deter him.

Nevertheless, the boy is determined to carry out the dangerous task and to marry Waltraute afterwards.

This novel is also known as I Possessed a Demon Sovereign

Chen Luoyang felt that something was wrong with his transmigration. After transmigrating, he possessed the body of the highest expert in the world, the Master of the Demon Cult, addressed respectfully as the Demon Sovereign.

Generally, aren’t supreme experts the ones that leave behind a wisp of their soul behind and occupy a new body of some miserable low-level youngster then they go on a journey of revenge and make a comeback?!

Or perhaps it would be transmigrating into a miserable youngster’s body and obtaining a cheat slowly walking the road to becoming a God?

But why did his transmigration seem wrong?

Now my environment is full of big shots and I feel like I’m going to be exposed!

- Description from Novelupdates

When our protagonist becomes the game character Jun Karentia, she thinks she has it made. She may be just a lowly support mage, but with her knowledge of the game, she knows she can finagle her way to the good ending following around the main character, Fabian. The problem? This game doesn’t end after one playthrough. Jun is prepared to guide Fabian through the second playthrough to the true ending when… Fabian abandons her. Now the Grand Duke Mayer Knox—captain of the Dark Knights and the secret final boss—is determined to have her join his party. Can Jun turn the final boss into the main character? Why is Mayer Knox so intent on having her in his party? And when will these rumors about being his lover stop?!