30+40 kruber main here.
The defensive talents aren’t very good. Your level 10 talent compounds after grims meaning it’s off until your last 1-2 hits taken from a trash mob; against stormverms and other things which kill people it does nothing. Defense on paced strikes at 15 isn’t bad but it’s not great either — if you’re using paced strikes well you’ll be stunning everything with your attacks, and again, 25% won’t save you from heavy hitters (nor would you have paced strikes up against them anyway).
Long story short you want to stack power talents. This will help you cleave, stun, and kill all targets in range. Put Swift Slaying on your weapon and take “And Stay Down!” to keep it active.
Executioner is viable but halberd is much easier to use, and honestly might be the best melee weapon in the game. It has exceptional range, armor pen, and can break a shieldvermin’s guard with one light combo. The first light is armor piercing and always cleaves all targets in range. Spam it by block-cancelling immediately after throwing it out. This has the added perk of actually blocking a hit once in a while even after you’ve started the next swing. Let me emphasize that mercenary is built to keep attacking! If you’re blocking you’re not using your paced strikes, bonus crit, bonus power, etc. and may as well be playing foot knight.
Lastly you want reduced CD on your shout. Your team can generate their own temp life and saving it to res people defeats its purpose — its perhaps the strongest ability for preventing damage through its space creation and special/boss stun. This is, for instance, the best way to save someone who gets hooked into a horde which is often a cause of death in legend.
Sorry for the long post but I hope you got something out of it.