Lol. I've also got profiles done for my siblings, Seijuro's rebuilt from the ground up, and Rouga's re-tooled for the fic.
Izuna Uchiha, Madara's younger brother. He had the motivation, knew Madara's history, and didn't necessarily have to die upon losing his eyes. Rather, he could've transplated a pair and gained EMS just like Madara did, making him powerful enough to act as Madara. Then, where Madara would go about setting up the ground work for the Moon's Eye plan, Izuna could've stayed in the background and found ways to extend his lifespan, thus picking up the plan and attempting to finish it after Madara's death. It would've worked almost completely in context too.
Izuna Uchiha, Madara's younger brother. He had the motivation, knew Madara's history, and didn't necessarily have to die upon losing his eyes. Rather, he could've transplated a pair and gained EMS just like Madara did, making him powerful enough to act as Madara. Then, where Madara would go about setting up the ground work for the Moon's Eye plan, Izuna could've stayed in the background and found ways to extend his lifespan, thus picking up the plan and attempting to finish it after Madara's death. It would've worked almost completely in context too.