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I absolutely love this manga, i haven't read something like this before and i am definitely regretting not reading it sooner, but i wonder...

Why did the soldiers drastically change like that? Were they brain washed, did somebody charm them, or were they scum all along but the new guy coming gave them a reason to act up on it? Or were they caught in his ideals and started changing their mind too? I am so confused... I really felt sad seeing the fluffy haired boy change so much...