Uchiha Madara accidentally picked up an amnesiac child who looked like his brother. He knew this was a conspiracy, but he didn't mind playing with them.
A kind of stand-in joke (among Uchiha). It shouldn't be considered a bloody affair, after all, I think these two people are quite sober.
I try my best not to be OOC, but my writing skills are limited, so please bear with me.
The age operation is eye-catching, a parallel world based on the original work.
Purpose: It is not necessary to forcibly reduce the character's intelligence