My Diamond Pickaxe build: the perfect heavy attack zaw.

I've experimented with putting this same meta heavy attack build on all weapons that have guaranteed slash procs, and this is one of the best. Probably the most useful. Nikanas are nice too, but have way too much forward movement on the attack. The [Dokrahm] is very controllable.

Put Exodia Brave on this, and you'll be constantly regenerating energy as long as you don't have a toggle drain ability on.

This build will one-shot most Steel Path enemies at normal mission levels. You can kill an acolyte in a few hits, or even just two if you're solo. You hit them and watch them bleed out. You'll run up to a Steel Path Bombard, hit him for like 5% of his health bar, then he'll bleed out the rest of his health in the next second. Same with heavy gunners.

If you're new to the heavy attack build, all of these mods work together to math a critical hit with really high raw damage, which wallops the hell out of your target with true damage when the blood proc ticks. [Corrupt Charge] and Glad Might work together to get you to a higher crit level with a combo count always at '2', and other mods, like [Killing Blow], Amalgam OS, and [Fury], make the heavy attack fast. You don't need Viral or elementals. Raw crit damage is the goal, and the weapon's stance forces a slash proc.

Take a panzer vulpy with you for viral procs to be even more overkill.

Update note:
[Reaping Spiral] is way better of a stance than [Stalking Fan] for those moments when you're doing normal attacks instead of heavies for some reason. If you care, add another forma or stance forma to change the stance.