A firewall without that skill? No, I don't think that's possible!
But there must be surtainly other ways to kill those enemies in a good way

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Try par example enchant a strong damage sword with strong poisondamage (Level 4 or 5 of poison-enchanting) or maybe with "fire curse" or "Life Leech" ?
Or improve your melee-skills?
And don't forget: there're par exemple also Mage-skills or Rangerskills that improve your fighting as a warrior .. try something ... I prefer to keep always 1 skillpoint in reserve most of the time.
Or use a bow? Or summon a undead on the moment you can see the enemie and than they attack also the undead and you can attack with a spell or bow ...
With 'my' strategy of battle I have kill in Orobas Fjords L18 enemies when I was L13! With a bow and Magic Missile and melee ... more than 1000 XP for 1 enemy
Most of the time I use one-handed weapon + shield, because a shield is good for protection, but not always handy! Yesterday I fight demons in the Mine with two-handed strong damage sword, very nice

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