Dragon Sovereign: Devour and Evolve!

Reborn into the world occupied by beasts, and incarnate into the Frost Dragon family whose bloodline has been weakened.
Fortunately, there are golden fingers at the beginning, killing + swallowing = strengthening points.
Before long, the legend of a frost dragon swept across the continent.
In the Frost Dragon Clan, he is honored as the Frost Dragon King!
In the seven elemental dragon clan, he is the monarch of the magic dragon!
The gods and demons of the plane are all afraid of him, just because he is a god slayer!