A powerful fire-breathing dragon in the West was avenged by a white-robed mage
Use the space splitting technique to send it to the ancient world of gods in the East
Because of the language barrier, someone used mind-reading skills to figure out that he was a dragon.
Then he was confusedly adopted as the remnant illegitimate son of the romantic Dragon King father who spread his seeds around.
So he became the only poor baby in Dragon King Ao's family who couldn't swim... The fattest one... And couldn't understand Chinese.