Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 404 - : 403

Cultivating his power by slaying demons and taming countless beasts, the emperor solidified his throne as the world's ruler. But not once in his life had he expected that his disciples would use research on demonology to sap the world tree's power and push the world to destruction.Trying to fix his mistake, he opted to use all of his cultivated power to cure the world tree and block anyone from sapping its power ever again. But in exchange, he was to lose all of his power.But...the worst had happened, his wife... had betrayed him.

Li Zhizhi was taken back to the capital at the age of fifteen to recognize her ancestral roots. As the true eldest daughter of the Li family, she should have been cherished. However, everyone preferred Li Suwan, who was knowledgeable, polite, and clever. As for Li Zhizhi, she grew up in a remote and impoverished village, ignorant of the ways of the world, and her name even carried a sense of disdain.

Shen Dongqing is a powerful, thousand-year-old ghost. He had just possessed a body and hadn’t even relaxed for two days yet when he was pulled into a white, parallel world.

On the first day of the Infinite Nightmare Game:
Other players tremble, crying and wailing wanting to go home.
Shen Dongqing eats, sleeps, and plays ‘Fight the Landlord’ (card game).

The second day:
Other players are chased endlessly by ghosts, crying loudly ‘Save me!’
Shen Dongqing eats, sleeps, and plays ‘Fight the Landlord’.

The third day.
Shen Dongqing……
The ghosts finally set their sights on this lazy player. The other players watch on in glee. As a result, who knew that this slim and pale youth would stand up and easily dispatched the ghosts with his bare hands.

Other ghosts: Can’t afford to disrupt this elder. Let’s go, let’s go.

- 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?!