Well girl, you have three problem.
1. MC come from different dimension in which he has no connection whatsoever to your world history.
2. The MC's world are only comprised of humans. Now hold your horse, if you're thinking that sound like a frigging paradise you'll be dead wrong. Every human that live on different region and continent, speak different and worshipping different gods consider themselves different race than each other and often back in the days used to oppress and genocide each other. These days? Not so much, but yes, still kinda happening in some corner of his world.
3. MC himself raised in a country that used to be militaristic and ultranationalist but got really humbled after picking a fight with way industrious country that literally can afford to send a barge, full of ice-cream, to their soldier while MC country told their own soldier to fend off for themselves without proper supply. Now the main thing is this, after that country got bombed twice with a power equivalent to a sun, they went and ditched the whole honor and militarism nonsense and went into semi-conductor industries, entertainment and well, porn, and pretty much gone pacifist and hate the idea of war itself.
You can see the problem now? MC himself will not raise a weapon for the sake of hate and pride, although he will do it to protect he really cares about. Psychologily speaking, you CAN'T subvert him to your cause. It won't bloody work.