Raul Serra

Raul Serra is the main human antagonist of Season 4 and a defected member of the Quatre Knights. He manipulated the protagonists and the other Quatre Knights so he could release the reversed Aichi's seals to fight him and inherit the seed of Void to conquer both Earth and Cray. He is also known as the South American champion in Cardfight!! Vanguard, and he is considered to be a top world-class fighter. After his defeat, he lost all memories of Aichi and the Quatre Knights, and was banished from the sanctuary forever. His fate afterwards is currently unknown.