Amazingly Strong and Stunning Lost Prince

Born of a servant?
Why does he look like one of the Prince of the kingdom?

John Crue was born of a servant mother but raised by a mistress of the Duke as a godson. When the Duke saw him he took him and trained him to become the next butler. This is all to protect him until his sixteenth birthday. He was indeed raised as a noble but when he reached his age and proved he is a royal, his mother was kidnapped and he also learned the true nature and status of his birth mother. With the Duke of the Battlefield, John will usurp his throne in the kingdom, or is it Kingdoms?

Knowing that everyone of royal blood is blessed with a supernatural power, will John unleash his skill to save the empire upon his return, or will he be taken away like his mother? How will he deal with the ruthless father whom have told him
“If you are of no power, you will be killed.”
While one of the assassins bow down to him saying,
“Crown Prince John Crue Ezekiel Croglin, the King ordered for you to go home”

What will his decision be?