Rudo is prince of the kingdom of Golt, where Lost Song takes place.
Prince Rudo is a cold, calculating prince who uses Finis as a weapon of war against a neighboring country. He has been shown to threaten and even kill people purely out of annoyance.
During Finis' second timeline Prince Rudo's hair isn't purple, but instead Blonde, matching Alea's true hair color. In this timeline Rudo has not declared war against its neighboring country, but instead opposes it. His father dies during the attack on the castle that was lead by Bazra. In the credit scenes he is seen during Alea's crowning as queen.