Douluo Dalu 2: The True God King - Chapter 242: [DD2]:

Looking at the survivors, their faces the picture of despair, surrounded by zombies at the foot of the towering walls, Tang Ye stretched his arms wide and shouted: “Welcome to paradise!”

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]

At 18, Alex Kain is whisked away to Eryndor, a game-like realm where he gains 'Skill Synthesis', a talent to fuse skills into godlike powers. Battling monsters and conquering dungeons, he builds a harem of strong women drawn to his might and charm. With the power to return to Earth bearing incredible resources, Alex faces a growing threat that endangers both worlds in this epic of adventure, romance, and ambition.

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.