Board Thread:Versus Debates/@comment-26636534-20170822151908/@comment-25122992-20170823165748

The fact that he later stepped out alive clearly speaks that he wasn't dead. Maybe only, he could've used Izanagi to cancell out his death. However, Itachi had enough knowlegde about Izanagi, while Obito himself said he stayed alive thanks to some things he kept hidden from Itachi. Since Izanagi wasn't a secret for Itachi, it leaves Kamui as the only possibility, meaning that Obito warped the flames away with the jutsu. But there's no reason to believe that Obito would be affected by the flames if he reacts in time to make himself intangible, with Kamui as well, since there's no way for Amaterasu to hit something that isn't touchable and technically resides in another dimension.