The protagonist became the character Daud Campbell in "Savior Rising," a game he enjoyed and became an veteran in. He possessed the body of a powerless noble living on the outskirts, and decided to live quietly, avoiding others' attention.

On his first day inside the game, he gets involved with the Final Boss, also known as the vessel of the Grey Demon, "Elnore Elinarize la Tristan."

After their encounter, the protagonist gains two special rewards : "Desperate Survival," which makes him stronger when his rate of survival decreases, and "Deadly Charm," which charms those who have evil traits.

Not only do these two skills get him entangled with the Final Boss, but they also get him entangled with other demon vessels. However, with the use of his skills, he calmly overcomes the challenges with his veteran expertise.

But every time he overcomes a challenge, those with evil traits become interested in him...

Finally, he received his end goal.

(Source: KakaoPage, translated)