Izuna Uchiha

Izuna is a fair-skinned man with spiky, blue-tinged black hair drawn into a ponytail, his centre-parted bangs framing his face. He wears the customary Uchiha attire, a high-collared blue shirt bearing the clan crest on the upper back with matching trousers bound in bandages at the cuffs, and a bandage belt at his waist holds a pouch for his tools. As a boy he went without the ponytail, his hair spiking out behind, and dressed in the high-collared Warring States robes with a crest and an armoured breastplate. Hashirama Senju once remarked that he looked strikingly like a later clansman, Sasuke Uchiha.

Izuna was a devoted, peace-minded man who longed for stability within his clan. He and Madara pushed each other constantly, sparring to sharpen their skills, and he idolised his older brother, stunned as a child when Madara confessed to being weaker than Hashirama and overjoyed when Madara's Sharingan awakened soon after. As he matured his love for the Uchiha only deepened, and he fought ferociously in their defence while holding a hard distrust of the Senju, warning Madara even while dying not to swallow Hashirama's hollow offers of truce. The anime adds that his Sharingan, able to pierce any attempt to blind him, left him pitying those born without the eye, and that he went to his grave still cautioning his brother against ever trusting the Senju.

Born to Tajima Uchiha before the age of hidden villages, Izuna was one of five sons, but three fell to the Senju, leaving him and his elder brother Madara. Counted among the clan's most gifted, he trained relentlessly against Madara and, still a child, joined his father on a strike against Hashirama Senju, only to be met by Butsuma and Tobirama; he traded blows with Tobirama while Madara deflected a sneak attack meant to break the deadlock between their fathers. As the clan wars ground on, Izuna awakened his Sharingan and, with Madara, became one of the first two Uchiha ever to gain the Mangekyō Sharingan, its pattern three bars fanning out from the pupil, and the pair rose to lead the clan. His talent was extraordinary even by Uchiha measure: he carried unusually potent chakra, matched Tobirama, one of the fastest ninja of the age, and in the anime wielded Fire Release and a blade with equal ease, driving the Great Fireball Technique hard enough to break through a Water Dragon Bullet. His life ended when Tobirama's Flying Thunder God Slash dealt him a killing wound; as Madara carried him from the field and Hashirama begged for peace, Izuna urged his brother to reject the enemy's lies. Dying, he pressed his own eyes on Madara so that he might claim the Eternal Mangekyō Sharingan and guard the clan, a sacrifice that many, seeing Madara's fading sight, wrongly blamed on Madara taking the eyes by force. Those eyes echoed down the years: they gave Madara his eternal sight, later fuelled Izanagi to cheat death, and in old age helped awaken his Rinnegan, before passing to Nagato and then Obito Uchiha, the latter waging the Fourth Shinobi World War in Madara's name. Madara nursed a bitter grudge against Tobirama for killing his brother, and Hashirama came to see echoes of Izuna in Sasuke Uchiha. Only when Madara reclaimed the eyes from Obito and met his final death did Izuna's eyes at last die with him.