Help Plz: Karlach very weak and Moonrise Towers Fight impossible

[Pod]

Just to preface this post, I am absolutely not understanding all the strings to everything and brute forcing my way through this game.

Karlach is Lvl 7 but her attacks are only doing 5-7 damage.
Her original weapon was a Greataxe (4-15 dmg) and I've only found one weapon to replace it, the Exterminators axe (5-21 damage), but it still always does poor damage. Lae'zel on the other hand is doing 15-30 damage which I like and expected of a Barbarian too.

This was never really a problem as the rest of my team carried every fight and Karlach was a good tank, but now I'm at the Moonrise Towers fight and getting my ass kicked.

I expect Karlach to be better so assuming I've done something wrong or missed something? I'm hoping that's true so I can have more advantage in the fight with her.

Thank you for any input!

[Bladeslayer]

If you are having problems change the weapon you are using or class. There are better weapons later on.

[Mork]

How much STR does she have?

If STR is not the problem, the easiest way to make her more relevant would be probably
5 barbarian / 2 fighter

Those 2 levels of fighter would give her Action Surge and the Two handed weapon style making the low damages rolls on her greataxe less likely.

After that, you should probably level her to 4 fighter for the subclass and the feat.

[Revan619]

Karlach is a barbarian and a beast. Respec her to go for 17 strength 14 dex and 15 con. Pick wildheart bear for her subclass. Level 4 pop those up to 18 strength and 16 con. Get the potion in moonrise for +2 strength to 20. Level 5 she gets a second attack. I normally give her a +1 axe or greatsword. Dip it in fire or poison for an extra d4 damage. You can throw poison on the floor or use a candle. Act 1 you can happily use bracers of defence to give her +2 ac

So she should be doing 2d6+8+1d4 per swing. Attacking with advantage from reckless attack. If you were smart and made a bunch of bloodlust elixirs and potions of haste in act 1 she should have six attacks a round.

Usually the end goal idea is 4 Wildheart 8 battlemaster. I usually respec around level 8 from pure barbarian to 5/3 then levels 9 and 10 both provide feats. The weapon I usually use you get from moonrise, HALBERD OF VIGILANCE. I get great weapon master, polearm master and sentinel. You can either use a bonus attack after a kill or a rear strike on the halberd.

With Karlach's coin ability and a weapon dip. Your attacks should be doing 1d10+18+2d4+1d8 with seven attacks a round all with advantage using battlemaster manuevers. You can use a variety of gloves to also increase damage by a d4 too if you want. She will also get a reaction attack when anyone enters her extended reach which also stops their movement for the round.