MTL - Marvel: Containment Foundation From Scratch - Chapter 19

After all, transmigrators of this era were no simple matter. Some became slimes, others turned into treasure chest monsters, and some were even reduced to mere skull--such things were all commonplace.It was nothing more than playing a villain, Shiayar didn't care. Wasn't it only natural to pay some price to become stronger?[Destined Great Villain System][“Let this world feel the agony!”][Newcomer Mission: Let the young and naive Grand Duke's daughter of the Azure Garden Dukedom, Miss Silvia, experience the betrayal of her loved ones and, amidst the pain and despair, complete her transformation and rebirth.]

Vainqueur Knightsbane is your average dragon: a giant, fire-breathing lizard who loves to take naps on his golden hoard, kidnap princesses for fun, and make the life of adventurers miserable. Vainqueur's only pleasure in life is to watch his treasure get bigger, one coin at a time.

So when a would-be thief turned unwilling minion tells him about "classes," "levels," and "quests," Vainqueur wonders if maybe, just maybe, he should consider a career change.

After all, why bother hunting monsters for free when you can get paid for it?

On his coming-of-age day, Argolaith’s mistake bound him to a mystical magic unseen in the world. As his powers grow, they threaten to reshape the realm—but can he master them before they bring ruin?

Waking up, Kim Hajin finds himself in a familiar world but an unfamiliar body.