I've had two barbarians in all my time playing Pillars. The first was an adventurer I tried to make into a tank, so I wouldn't have to take Eder everywhere. He didn't do too well. Mostly he couldn't withstand enemy fire very well, and dealt little damage. He did frighten and sicken enemies, but that just wasn't enough.
Then I got White March and recruited Maneha. She was a decent enough damage dealer. Heart of Fury does chew through mooks like popcorn. I kept her as a dual-wielder, since I hadn't used that style much before. It's a shame her 1st level pick is Frightening Yell... I feel like it loses value eventually.