Just keep training and get your level up. While training you should receive items after winning. Sell them and buy the best available weapons and armour as well as upgrading your skills. You should soon be able to defeat him!
NOOOOOO!!! You fools. The easiest way to kill the Baron is to use Regulate to get his focus to zero. Then he'll use the 'Deep Burning' debuff on himself, recovering vast amounts of focus but doing like 4000 damage to himself. Eventually, he'll start to get the 'Holy Scars' debuff, allowing you to land crazy amounts of damage to him. Biological is the easiest class - and also the best for this fight. I suggest you restart, then use Biological, as Disrupt will kill him FAST.
It's not training you need, just leave Roald behind. You see, the Baron loses a lot of health to recover focus, and the only move that he can use without focus is recovering all his focus. So Roald will keep using moves to disable focus, and the Baron won't take massive damage. Once he's out of focus, he uses a move that makes him lose a total of 10,000 health. So leave Roald behind, use the right combo of moves, and you will win for sure.