Dragonborn: Ouroboros' Oath

My name is Peng Chen, the legitimate son of the Peng family in Longxi and the heir to the family head. When I was six years old, an Ouroboros mark appeared on my chest out of thin air, which was exactly the same as the mark on the chest of Peng Zu, the ancestor of the Peng family three thousand years ago. Since then, I have an ancient bronze book in my mind. As long as I kill a dragon, the pages of the book will light up. Every time a page is lit, I can inherit the dragon's exclusive ability. The hardened dragon scales of the third-generation species, the lava breath of the second-generation species, and even the original spell of the Dragon King, as long as I can kill them, I can turn them into my own. During the adult trial at the age of sixteen, I broke into the Bronze Dragon Tomb alone and killed three generations of bronze furnace growers on my own. And deep in the Dragon Tomb, he found the bronze key that his father left behind before he disappeared, with a line of words engraved on it: Achen, I will wait for you at the end. My mother told me that the secret guarded by the Peng family for three thousand years is a door deep in the Dragon Tomb that leads to the tomb of the Black King Nidhogg. And my father walked through that door ten years ago and never came back. I decided to go to Kassel Academy to find out all the truth and find my father. There are already undercurrents on the road ahead. The Three Gorges Bronze City, Beijing Nibelungen, Tokyo Longyuan, Nordic Odin Realm... The four kings are awakening one after another, and the shadow of the Black King is also quietly dormant in the dark. I will clear out the dragons that block the road one by one; I will complete the path I should take step by step; Regardless of fate or mystery, I will personally go to the end and reveal everything.