Board Thread:Versus Debates/@comment-29899821-20160317090255/@comment-734582-20160403165557

Ishi208 wrote: All I know of is that it's said in the Manga "A Sharingan that can activate Susanoo is a rarity", it's not saying A Mangekyo Sharingan that can activate Susanoo is a rarity. I don't see Tobi even implying it. Since a regular Sharingan can not activate Susanoo to begin with, it's clear that he's referring to the Mangekyou.