Good and FUN Zealot Build
 Zealot Build - Warhammer 40k: Darktide 

This is my build that I've developed, evolved, and used for over 1060 hours in the game.  As you will see below, this build started out based on a lot of personal preference and flawed decision making as I was a noob to this Genre, but it has evolved as I got more input from reddit and as the game got updated. The only things I refuse to change are my weapons - I wanted to use the Agni Mk Ia Shock Maul because I think it looks cool and would probably be the melee weapon I would choose to use IRL, and I LOVE the Zarona Mk IIa Quickdraw Stub Revolver because I own a revolver IRL and they are awesome.  The Talent Tree is suited towards Toughness Replenishment, Toughness Damage Reduction, Melee Damage - as the revolver doesn't need boosting from the talents - and Critical Hits.

Based on my observations on other builds and opinions from reddit, the glaring "mistake" I'm making is not choosing Duellist.  While I originally didn't take it because I never dodged and just face-tanked everything, now I dodge more but there is a glitch with Duellist wherein it doesn't show up on the bottom of the screen when it activates. If/when they fix that I'll play around with it.

Play style is mostly Frontline melee and then whipping out the revolver to take out any elite or larger units, particularly Ragers, Trappers, Snipers, and distant enemies. 

I really enjoy this build, but any suggestions or recommendations are welcome! 

EDIT:  After some great input from Reddit, I've made a few changes, getting rid of Faith's Fortitude and Enemies Within, Enemies Without, in order to pick up Scourge and Enduring Faith. I got a lot of good feedback, so this is still a work in progress, especially with respect to my use of Dodge and Dodge based talents. 

EDIT:  After reading the descriptions of what each talent does mathematically in game, I switched Blood Redemption out for Enemies Within, Enemies Without.  Still working on using dodge and Fury of the Faithful more and more effectively to better take advantage of the related talents. 

EDIT:  Picked up Redoubled Zeal and Purge the Unclean after trying some higher difficulty levels. Got rid of Enemies Within, Enemies Without and Fortitude in Fellowship for now. 

EDIT:  Updated curios' third perks to what I plan on making them after the itemization update. 

EDIT:  Now that the update is out, I've changed Hammerblow to High Voltage on my Agni Mk Ia Shock Maul to see if I get more damage output (plus the Maul seems to have enough stagger), and changed Toughness Regen speed to another Gunner resistance on one of my curios. 

EDIT:  I made all three curios have resistance to gunners as that seems to be really helpful. Also updated some of the roles for my build. Since the update, I haven't seen a need to change my talent tree much. I like Stalwart even more now, even though most folks pick Fury Rising. I like the defensive nature of Stalwart and I seem to trigger Fury whenever I want or need already. 

EDIT:  I have been playing around with my Curios lately, trying to figure out if Toughness or Health is better for me. I just finished two games, one with 3 Toughness curios and one with 3 health curios, and I'm not sure I could tell too much of a difference; of course it's hard to test things like this in a game where there are so many other variables at play. For now I'm gonna go with 2 Toughness and 1 health, but I'll continue to experiment.

EDIT:  Moved to 1 Toughness curio and 2 health curios. With all the Toughness Replenishment and Toughness Damage reduction my build has, I'm keeping Toughness high but health continues to be a problem. I'll keep experimenting I'm sure. (If/when I do switch curios, I'll update them above, but won't update this post with an edit each time I do.) 

EDIT:  Switching The Master's Retribution for Invocation of Death to see if I want to spam Fury of the Faithful more than the 2 I already have with Redoubled Zeal.

EDIT:  THEY MADE A CHANGE TO Blood Redemption WITHOUT MENTIONING IT IN THE NOTES OF THE LATEST NIGHTMARES AND VISIONS PATCH. They buffed the Toughness Replenishment from 50% to 100%.  I've taken the Disdain talent point away and put it in Blood Redemption to see how I like it.