Avoid Yandere Constellation - Chapter 169:

Getting transmigrated inside a novel is not really a bad thing—you know the story, you have the power of the future in your hand, you know all the hidden keys. You might as well end up as the most powerful and omniscient being in that world.That is, if you don’t wake up during the epilogue.And yet I find myself in the body of a fallen priest at the end of the novel, a tragic hero who had his mana circuit broken in the last war, being shunned, drown in debt, and destined to die not long after.Fortunately, I know just the cure.Unfortunately, the cure was in the hand of one of the Demon Lords—you know, the race that my kingdom just wage war with.Would he give me the cure if I asked him politely? There’s no harm in trying, right? I’d die if I didn’t get the cure, anyway.“Sure, but you have to be my bride as the price,” the Demon Lord said....huh? Sir, you know I’m (technically) a priest, right?

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 –

The more he got to the Comprehensive world, Beiyuan Baiqiu originally thought it was just an ordinary Comprehensive daily world.

Who would have thought that after entering high school, unusual things would happen one after another, and I would awaken myself through the simulator.

Since then, Beiyuan Baiqiu has embarked on the road of being invincible.

[Demon Slayer, Campione!, No Game No Life, Problem Children are Coming from Another World…]

- Description from novelbuddy