Fate/The Prince And The Assassin

The Crown Prince. A title meant to be for Hiro, but was stripped from him by the Prime Minister of the country of his Father and Mother.

Hiro valued the title, but never over valued it. So when he was stripped of the title he didn't try to take it back, but when the crown was given to his younger brother, Hiro finally understood why.

He understood that the Empire was corrupt, yet he did nothing. He watched it turn to what it was now. He watched the Empire of his Father and Mother turn corrupt without batting an eye. He watched it with an uninterested look.

Learning of the Rebel Army and it's assassin group, Night Raid, he joins them not to save people or free the Empire from corruption. He joined them looking for a purpose. The spark that had died all those years ago.