"Izuna was noted to be of prodigious talent, even by the battle-adept Uchiha clan's standards, and was one of the most powerful Uchiha in history being his brother Madara's equal before Madara acquired the Eternal Mangekyō Sharingan."
I don't see anywhere it listed this, the only part of the databook that said izuna was equal to anyone was tobirama not madara. and if it did say he was equal to his brother, i'm sure it was before they awakened Mangekyou. If i'm correct, then please change that in the wiki part.