Punisher's 'Forecful Shock Maul' Break the Line
 Arbites Build - Warhammer 40k: Darktide 

They did it boys, they made the Shock Maul usable...

On the Arbite specifically, because of Drive Them Back, and even then only just barely. 

This build basically copies the homeward of the Suppression Shield build, but I swap Soulguilt Scan for Strike Down because the base shock maul can use the rending much better. Beyond that, I see no reason to 'fix what ant broken', especially since the dog is just super useful passive damage that is very much needed given while the Shock Maul is decent, it isn't 'Arbite Shock Maul' broken. 

It still does some incredible work though, 3 tapping a crusher after poking it with your shocky stick, and otherwise being able to work through the wave pretty handily. It still gets stuck from time to time, but at least now you can largely fix that issue by pushing and then going back into your combo. Said combo being a simple light heavy, or a push into light heavy again. One then pokes to electrocute tough enemies, and heavy lights them to death when needed, or one can skip straight to the heavy light if one charges up thrust first. High Voltage means you'll always be able to clean whatever you hit up if it doesn't die to the first swing, along with all the various stagger and force bonuses given to you by the stat stick that is the Arbite tree.

I then use the Agripinaa Revolver just for the sack of variety, it does good damage is able to kill most targets from range in 2-5 shots, and is relatively fast to reload so I don't need Judicious Efficiency. It also makes up for not having Soulguilt Scan with Trickshooter, so even if I do happen to hit the fact I'll still get stacking bonuses for it. Works quite well, and the dog with Remote Detonation easily makes up the difference. 

Easily able to clear waves, easily able to deal with anything that comes your way, you'll just be slightly slower than most people because you have to 'prime' the target first. But you can finally use the Shock Maul without malding, it's just to bad it's on the class that has a strictly better version of it already.