In my last hardmode run he was main damage dealer, completely outdamaging barbarian and mino thrower.
I made insectoid fighter in a back row with quick and martial training traits, all stats into dex and willpower (because I need more energy for special attacks and don't want them to miss). Lizard fighter with fast metabolism can be good here too.
I skilled him acc 2 -> heavy 5 -> crit 5 -> more acc or con 3 for more mana.
I gave him archmages set + braclet with -15% cooldown (very good benefit on special attacks) + 50 energy amulet + bear gloves + shaman or fast energy regen cloak and all energy boosting books.
At the end he had about 300 enegry. For common fights my favorite weapon was Ancient Claymore (I rushed Pyramid early for it). Why not Bane? Let's compare them.
AC: special attack hits about 250-300, crits for 500-600 (enough to oneshot common mob), cooldown is about 5-6 secs with my gear, costs 30 energy
Bane: special attack hits about 300-350, crits for 600-700, cooldown is about 10 secs, costs 60 energy
As you can see, you can perform almost twice more specials with Claymore in the same time and same energy, each of them is only 15-20% weaker then Bane.
So you can start every fight oneshoting most dangerous enemy without trying to control or backstab it, and after 6 secs you can repeat it again.
Try it yourself and you may find it's very comfortable to play like this instead of trying to click many hits with light weapon and making many dodge moves.
Now balance breaking thing
Just use Scythe, 10-15 rage potions and one speed potion, you will have more than 200-300 str.
Cooldown of Scythe special attack is less than 3 secs, it will be 1.5 with speed potion.
It's not very much damage if it doesn't crit (but enough to oneshot zombie or rat) but if it crits (with 25% chance) it does 2000-3000 damage.
In my playthrough both Dragon and Master were oneshoted with such crits.