DonnEll
He can fight the witch clan and whoever else even thought they are ridiculously overpowered but not fight in a war he started sure makes perfect sense i see it clearly nowđ so dumb but whatever!
Wait what? You don't want him to fight the Witch Clan which was you said overpowered. Instead, you wanted him to join the war which clearly contained factions stronger than Witch Clan? Which Clan only had remaining 3 shackled realm yet the Union Peace had more than 20 shackled realms, right? And you said it's better if he joined the war which is not his goal? Souta only came to central continent to complete the chain quest. I doubt he would care about those people that he didn't even know. It's possible if it was Lumilia, Bryan, Brando, Alice, Cluster, or Yujin's family but unfortunately not. Union Peace isn't the only one hunting him even the second strongest faction Night Watch and the current Witch Clan is nothing compared to it.
If there was ever a quest where he could exceed the designs of it, this is certainly one of them. Fighting the control with the parasite or getting the uncles help in ending his life before the control takes over are possible. But with Souta automatically assuming he has no choice but to fight basically throws these possibilities out the window. Just food for thought...