MTL - World of Cultivation - ~ Eighty-three phoenix festival

We were a peaceful people living in harmony with nature in the vast lands of Lyréanor, but this peace was short-lived when our people were defeated by the dark elves, an ancient people even older than this world. It is said that they arrived in Lyréanor by boat and since their arrival, chaos has been unleashed. Proud of their obscure power, derived from dark rituals, they have raised gigantic armies of monsters whose name is synonymous with terror: ‘Obscurus’.They went on the rampage, and everywhere they went the grass didn't grow back, life died and disintegrated. Seven, there were seven. The seven dark elves known as the Lords of the Apocalypse. A single gesture from them was enough to strike us all down, a single gesture from one of them was enough to decimate us in blood and terror.And as I, Foster, contemplate the macabre scene before me, the bloodied and deformed bodies of my fellow elfes beings, and as death grips my soul, a strange sign appeared before me.[Ding... Activation of the world tree system]

Riven was a young man with dreams as vast as the horizon, but life demanded sacrifice. To support his struggling family, he gave up his education and ambitions, shouldering endless work to keep them afloat. Yet, his loyalty was met with the ultimate betrayal by his own father.As his life slipped away, Riven awoke in an unfamiliar world brimming with magic, reincarnated by a mysterious system. Gifted with a peculiar mana heart that pulses with untold power, Riven is thrust into a realm of mages, monsters, and ancient secrets.Determined to rise above his tragic past, Riven vows to become the strongest mage in this new world, uncovering the mysteries of his strange mana heart and the enigmatic system that guides him.

Xia Zhijun got the title ‘study god’ after scoring first place in the whole city. He’s the model of a good student in a teacher’s eyes: good grades, good manners, and quiet. When he wasn’t smiling, his entire body emits a cold abstinence aura. The girls only have the guts to look from afar and not get close.
Later, it was rumored throughout the entire school that even the study god would fight and hit on girls. Whoever dared to provoke his girl, he would teach you how to be a person at every minute. The night of the graduation ceremony someone saw him blocking Gu Siyi in the corner. He didn’t stop kissing even when she cried. He bit her lips and said in a raspy voice, “I’m going crazy…”
During college finals, Gu Siyi almost bursted out crying, “I’m such a failure. I won’t be able to find a good job in the future…And if I can’t find a good job, I can’t provide for myself…”
Xia Zhijun played with her pink earlobe and remarked, “I’ll take care of you.”
After they graduated, Xia Zhijun created a research company and Gu Siyi became the boss’s wife.
The commercial rocket, “Star of Siyi” was successfully launched. So everyone knew that the new technology superstar, Xia Zhijun has a wife who he spoils a lot.

- Description from Novelupdates

When I was reborn in South Korea, I wanted to live my life in peace. Pass the activation system, unlock the 'Big Brother' career, obtain the invincible system, and embark on the road to power