Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 643 - 642: Descend into Hell

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Lin Yan had transmigrated into the world of Immortals and had become a Heavenly Emperor who was already defeated by the Male Lead along with the ten Female Leads at the beginning of the plot.

But as Lin Yan was about to die, he awakened a power that he could use to rewrite his past doings.

So, Lin Yan has begun to rewrite his past.

When Lin Yan was still a child, he struggled to feed Xiao Yanran, one of the female leads, who was then younger than him. He had to strip his Supreme Bone and give it to her, protect her from the obstacles. He made a vow, “As long as I am here, no one will be allowed to bully you.”

Later when Lin Yan’s cultivation rose , he had run into Xiao Mei, yet another heroine, and the two of them spent time together and eventually got married. When the Devils were about to invade their world, Lin Yan said staring right into his wife’s eyes, “I will protect you with my life…”

And soon he rose to become the Heavenly Emperor.

Everything he did was to shelter his loved ones and to protect the world.

However, his actions were misunderstood by the world.

…

Let’s see what all Lin Yan had done in the past…

In the year 298 from the era of the gods, elementary school girls Sumi Washio, Sonoko Nogi, and Gin Minowa are tasked with an important mission. They are to become heroes and fight Vertex, a mysterious enemy that is attacking Shinju-sama, the god tree that protects Shikoku, the only area in the world that is still habitable. What they don’t know, is that this fight will cost them more than they could have ever imagined.

In an exhilarating twist of fate, Jiang Chen traverse into a fantasy realm novel he read, taking on the role of the notorious Holy Son in a riveting tale. But here’s the catch – he’s pegged as the female lead’s obedient doglicker. Or so the story initially wanted…Unleashing the ‘Slack Off System’, Jiang Chen flips the script! Each act of slacking off spectacularly rewards him. Doglicking duties? Jiang Chen smirks at the thought. “Not in a million realms,” he declares.As the system chimes melodically, rewards rain down like immortal gifts:Ding, for successfully slacking off, you receive: the Emperor Weapon, All-Heaven Mirror!’Ding, another round of slacking off earns you: the Immortal Technique, Great Daluo Heaven!’Ding, for successfully slacking off you received: Immortal Emperor Cultivation!’But wait, there’s a twist in the tale! The world around Jiang Chen starts to unravel in the most unexpected ways.The character settings of the female leads have all collapsed.Junior Sister Ye Qingcheng: ‘I can only repay your life-saving grace with my body!’Cold and aloof master: ‘Disciple, I allow you to defy your master.’