Godstealer - Chapter 19: Year 3: Awakening True Potential

Amakawa Haruto died before he’d the chance to reunite with his childhood friend who disappeared five years ago. Rio, a young boy living in the slums seeks revenge for his mother who was murdered in cold blood in front of him when he was only five years of age.

There exists the earth many knows of and there exists an alternate world. Two people, each with their own backgrounds and values. For odd reasons, the memories and personality of Haruto, one who should have died resurrects in Rio’s body. As the two are confused over their memories and personality fusing together, Rio (Haruto) decides to live in this new world.

Along with Haruto’s memories, Rio awakens an unknown but special power. If he’s to use it, it looks as if he can live a better life, but before that, Rio encountered a kidnapping which results in involving the two princesses of the Bertam Kingdom.

After saving the princesses, Rio is given a scholarship to attend the Royal Academy, a school for the rich and powerful. His background being a poor orphan who once lived in the slums, the school full of nobles was rather a detestable place to stay at.

220 years ago, in the legendary Dragon Demon War, Hero Azell ended the war by killing the evil Dragon Demon race’s King Atein. He was able to save the population, but as a consequence, he was cursed. While he was dying, the high magician suggested a gamble that might save his life.

Transmigrating to the disciples of the Demon Sect, and relying on the skill modifier to become a giant of the Demon Dao.

[Detected the technique “Blood Nerve”, relying on devouring blood to practice]

[Side effects: easily affected by the spirit contained in the blood, becoming bloodthirsty, bloodthirsty, mad, and even brain dead]

[Please wait a moment, the system is being modified…]

[Ding! The modification is complete, and the side effects are cancelled]

- Description from novelbuddy

In a world where its inhabitants can destroy a city wall single-handedly, the empress has a kirin as her pet, and the imperial palace of Great Xia has a pool containing a dragon. There is also a Sword Mountain where spirit swords occasionally leave in search of a master .