Knowing full-well that their power was more or less evenly matched, in order to gain the upper-hand as the four of them clashed, Butsuma and Tajima — again thinking along the same lines — decided to target Izuna and Tobirama respectively, hoping to use the shock of a parent losing a child before their very eyes as a method to gain an advantage. However, their attacks were stopped by Hashirama and Madara, who had turned in time to see and prevent what was about to happen. Seeing the attack on his brother as an unforgivable act, Madara declared that they had reached an impasse, noting that their pipe-dreams would die there. Determined to fight, Tajima enquired whether or not Madara was prepared to take them on, but Madara noted that Hashirama was stronger than he was and the outcome would not be in their favour. As they prepared to depart, Madara stated that the next time they would see each other was on the battlefield as Uchiha and Senju, activating his Sharingan for the first time. Thus began the non-stop battling between the two, and eventually, the two would inherit the leadership of their respective clans. During one such battle, Tobirama fatally wounded Izuna on the battlefield. Despite the fact that Hashirama once again attempted to broker peace between the two clans, Madara refused and left the battlefield with his injured brother. In time, the fact that the Uchiha were inferior to the power of the Senju became abundantly clear and defectors began to come to the Senju side. The next time they met on the battlefield, Madara had acquired the Eternal Mangekyō Sharingan and remarked that his brother had died from the wound Tobirama had inflicted on him. Despite his new-found power, Madara was still defeated, but Hashirama, still seeking peace, halted his brother from killing the Uchiha and asked Madara if the two of them could not settle it like they used to. To this, Madara declared that they had lost his trust and the only way to regain this was if Hashirama were to kill himself or his brother.