Thanks @Boeroer, @Kaylon, and @Chaospread for the advice. I decided to go with a Berserker. Interestingly enough I found only one build that was for a single class berserker: https://steamcommunity.com/sharedfiles/filedetails/?l=ukrainian&id=1445712988&searchtext=Cerca+tra+le+guide+di+Pillars+of+Eternity+II%3A+Deadfire
But it didn't have human as a race, so I wasn't sure how effective playing as a human with that build would be. But I did find that there seem to be more multiclass builds with the Berserker as a subclass than single class ones, so I think I may just end up choosing one of those even if single class is typically recommended to new players. Now the issue is choosing which one to use. I'm still gonna play with companions and in relaxed difficulty.