Rise of the Iron Mage

What if Anthony Stark had an English aunt and cousins? What if Sirius stayed with Harry and Hagrid instead of running away to find the rat? What if Voldemort decided to end all of the "prophesied child" family. Muggle or otherwise, they could prove a challenge. He sent Bellatrix and the Lestranges to deal with the muggles. That threw Dumbledore's plan of the blood wards away, until Sirius mentions the existence of Lily's only living cousin: Tony Stark, the Iron Man, Hero of the Battle of New York and Avenger.