Dungeon Battle Royale ~ Since I became a Demon King, I will aim for World Domination - Chapter 2

Lingyun, a fierce and savage cultivation genius takes over a dead teenager’s body. Coincidentally, they are both named Lingyun. Set in a alternate version of the 21st century, teenager Lingyun has been killed by someone with a grudge.

- Description from Novelupdates

On the brink of destruction, I regained consciousness and found myself back in the past, 20 years ago. In order to have a peaceful retirement, I must prevent the impending doom.

“Do you like me?” “Yes...” “When did it start?” “A long time ago...” “Will you always like me?” “The fireworks...will always be with you...”Looking at her upturned face, the girl's timid hand was gently lifted up. The warmth in her palm has always been so familiar. “Want to go watch the fireworks together?” “Yes.”The summer fireworks blooming in the deep night are just like your touching and tender smile twelve years ago.----------------------------------PS: Youth daily life story, childhood friend single female protagonist.

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.