Becoming evil makes you ten times stronger, but becoming a demon gives you hundredfold strength - Chapter 474 - 362: The Land is Charming and Full of Passionate People, Since Ancient Times Beautiful Women are Paired with Heroes

As a child with an unattainable dream, I yearned to become a Hero, but I veered off the right path. Looking back, my aspiration to save others was nothing more than a foolish dream. I now realize the magnitude of my sins and the impossibility of atoning for them.

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

After the gold medal teacher, Sun Mo of the city’s No. 2 Middle School, fell into the water, he transmigrated to Tang Guo, Zhongzhou Academy and became a newly graduated intern teacher. Sun Mo bound the Peerless Master System, turning waste into little geniuses. Under Sun Mo’s guidance, the little children became masters after one year, passed emperor level after three years, and attempted god level after five years.

Ayaan is a young resident aspiring to be a surgeon, the final stage of a full on graduated plague doctor. However, in her attempt to redeem herself after a sudden discontinuation, she finds herself unravelling mysteries about her institution that are rather gut wrenching. Stick around and watch her persevere in a world full of monsters; creatures and humans alike.