From Today, I'm a Player - Chapter 259. Ragnarok

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.
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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!

To correct the mistakes of his past, a young man is forced to narrow the space between science and witchcraft, as he ventures on a quest to save his world from complete destruction.

Mike’s life used to revolve around two things: his girlfriend and his work.It was a peaceful existence—no drama, just an ordinary but sweet life.But just when he thought it would last forever, everything changed in the blink of an eye. His world was thrown into chaos when he was diagnosed with Stage IV lung cancer, with doctors giving him only three months to live.His girlfriend of three years left him for another man after he refused to give her his savings from the past two years.Mike would rather spend that money on alcohol, temporarily numbing the pain of his impending death, than fund his ex-girlfriend’s new life with her lover.Then, one day, while accidentally eavesdropping on a conversation in a restroom, a spark of hope ignited in his dead heart.Without hesitation, he signed up as a beta tester for a groundbreaking game—one that allowed players to enter other worlds. In each world, his mission was simple: save the heroine, and she could return with him to the real world.The most incredible part? These heroines would continue their lives and even keep their pre-existing occupations!His first world? A realm where the heroine, clad in a white coat, awaited him like a knight in shining armor. She was the first doctor to ever develop a cure for cancer!From world to world, universe to universe, Mike was followed by a growing number of beauties—each one willing to leave everything behind to follow him into his world.

I was proposed to by the Final Boss.