Obito, Madara, Izuna, Sasuke, Shisui, Itachi, all awakened their MS the natural way, by extreme emotional distress, unfiltered of DNA additives. (Shisui we may never know exactly how, but its plausible to conclude the same) but the difference between Obito and the rest, is Obito not only awakened his MS by severe emotional distress, but also with Senju DNA (hasih's cells) coursing through him. The durability and might of his MS was increased to EMS levels, and this is why his MS never lost light compared to Madara, Sasuke, Itachi, and even Kakashi.
Its now confirmed through Kakashi that Obito would have had Suasnoo, and with Kamui attached to Susanoo would make him have the mightiest sharingan.
Its now confirmed through Kakashi that Obito would have had Suasnoo, and with Kamui attached to Susanoo would make him have the mightiest sharingan.