So why exactly didn't his family move together with him, as it would normally happen in reality when they'd be apart for 10 years otherwise?
Getting revenge on the holy knights who watched your family get killed makes sense, so far I'm following, destroying the village you are stationed at so the term ends earlier, when you don't have anything to return to, not so much.
Also I can already feel the vomit rising up when the MC says "He needs someone to stop him". This man has not only murdered other holy knights, he also literally fed the villagers he was tasked to protect to the (were)wolves, propagating the very suffering he experienced himself. I don't want to see any kind of redemption. The only kind of stopping this man needs is with a swift thrust through the heart.