Question: is aegon a real targaryen?
Answer: The Fake Aegon theory suggests that Aegon is not actually the son of Rhaegar at all and that he is actually a Blackfyre claimant. House Blackfyre does not feature in the show but they are essentially Targaryens who descended from some of the legitimised bastards of Aegon the Unworthy (Aegon IV Targaryen).