While Madara is often ahead of most of their clan, before acquiring the Eternal Mangekyo Sharingan, Izuna’s strength and abilities were on par with his brother. Izuna was featured in flashbacks ...

Using the power of the Ten-Tails Juubi, extremely powerful wielders like Madara and Kaguya can open the third eye on their forehead to combine the power of the Rinnegan and the Sharingan.