Dragoon - The way to the dragon knight - Chapter 67

A decade ago, the first dungeon gates appeared, but some vanished before they were ever conquered. The MC, a low-rank hunter, awakens the Lost Gate System, granting him access to these forgotten dungeons where legendary monsters and artifacts are trapped. Each completed lost gate grants him absurd power, but also reveals terrifying truths—these dungeons are prisons for ancient beings who want revenge.

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates

Viserys Targaryen was born with the blood of dragons and yet lived his life in exile. He was a prince with a lost kingdom and a fading legacy, an immature bastard who died a pitiful death. Unfortunately, that same death was coming for me now… as I found myself in his body right before molten gold fried my brain.Yes. Fuck Khal Drogo, and fuck the molten crown.With the memories from another life, in this world of betrayal and broken oaths, I had the chance to forge a new destiny for myself. Armed with the knowledge of the future, my own cunning, and [The Dragon System], I made the choice to flee from the Dothraki barbarians and take back what was rightfully mine.

A necromancer and a saint blessed by the Constellations. That’s me.