Review Detail of Somer in System Nemesis

I thought his purpose was for revenge? then in 12 why is he conquering villages and being cruel and tyrannical to the innocent villagers? Not those that attacked him though. He died in his village attacked by monsters and now he's taking over this village and if they don't surrender its death, he is becoming no different than them. Might as well be a weakling was low all his prior live and now has an opportunity with a system to be what he seen from others and doesn't even care about revenge just doing what he couldn't previously. I get the class may affect his personality but it a totally different person at this point a mixture between his old self and necromancy in a way. The story is good though just seems to be a plot hole with the characters' abrupt change in character, that really has no explanation except the class from the system meaning he is a puppet to the system and class. But the story is pretty good.