Yasashiki
Genin at 4? Sorry just wanna make sure I'm not confused, don't kids attend the academy when they are 6-8 years old? They become genin after a few years later right? How did they become genin at 4?
Yasashiki:They stayed at the academy for two years, so they graduated at 6
The whole "cockblocking" Nawaki out of existence wouldn't have had a results yet. When Nawaki died he was twelve years old and Tsunade was 26. If the mc still had any working brain cells he would've realized by using simple subtraction that the age gap between both of them is pretty substantial. Nawaki was born when Tsunade was fourteen years old so there's no way he could've stopped them from having him yet. Apparently basic math skills weren't a part of the OP powerset that ROB gave him.