DesMark
i think u need to work on ur MC he's pretty muted and not in a good way. Every aspect of his character is just lacking like there could almost be something there but u move on or keep it shallow or the focus is shifted to something or someone else. If ur trying to make an Itachi adjacent character then I suggest u read Itachi scenes to understand why he's liked. Also Naruto as a series is pretty easily researchable if ur not sure about something.
This war should be the core thing to change MC's stand point and personality, colder and more calculated with a hint of being a battle maniac. War changes people no matter what they believe themselves to be. No matter how much of a sunshine and cheerful someone is before war, after experiencing war, they wont be the same person anymore, they would be battle hardened individuals and some weak willed few will come back with PTSD and other psychological problems.