Sorcerer's Handbook - Chapter 486: Secret Toxin of the Rainbow Tail

A 29 year old civil employment exam student wakes up in a blank white room and meets a baby angel. This baby angel informs him that he died in his sleep due to heart disease like his father and grandfather. Remembering his mom and their last conversation he says that he will take on a series of life and death tests that the baby angel offers him. From this point on he must put his life on the line and fight in the stage called ‘Arena’. And Every time he clears a test he will gain abilities and weapons to increase his strength. All to clear the tests and get his life back. This is his story of his fights in the ‘Arena’.

A giant golden tortoise, as huge as the world, crosses a broken world.

Seeing the vast world in ruins, Xu Feng slammed the giant golden tortoise on the head.

“Be careful next time, don’t use such brutal methods.”

The story begins with a young turtle-raiser who wants to live a stable life in a small family.

- Description from novelbuddy

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!

Lin Wu was a university student that died after having one too many energy drinks and then reincarnated into the body of a worm. He awakens to find out that he now has a system, but even it doesn't have a clear idea of where they are.

He comes out of the ground and discoverers that he’s no longer in his previous world but rather in a cultivation world.

Witness Lin Wu’s journey as he worms his way to the heavens from a tiny worm crawling in the ground.