Aurelius Dumbledore

Aurelius Dumbledore is the son of Albus Dumbledore and Sheila Rookwood. He joined Gellert Grindelwald as revenge on his father Albus for abandoning him and his mother Sheila when he was a child. Gellert sent him to kill Albus, but he failed. After Albus apologizes to him for abandoning him, he left Gellert and moved to Albus's side.