If you're playing Fat Shark's co-op survival shooter, Darktide, and you're trying to get the penance "On Overwatch" completed as the sharpshooter you're probably pretty frustrated at just how easy it is to fail. The conditions are pretty atrocious - Play a mission on malice difficulty or higher and finish without ever getting hit by melee. It's likely going to take a lot of tries to get this done, even with a full group of friends watching your back. I'm here to tell you how I did it and show you the build I used in the hopes that if you're struggling maybe this information can help you out just that much more.
First and foremost I'm going to suggest you not even try this in a serious fashion until you reach level 30. You're going to want to call on all your feats to make yourself as invisible to the enemy as possible while also still being a supportive teammate and dealing damage when you're needed.
Try and stick to level three difficulty missions with low engagement conditions. This is the minimum difficulty to complete the challenge and of course the fewer hordes running at you the less chance you have at getting beaned by some poxwalker while you're trying to reload. You'll definitely want to play at the back of the pack, but remember to put yourself against the wall any time you're given the opportunity. Enemies come from all sides all the time and it's very easy to be caught off guard.
I did this with a bolter and a chain sword because the bolter hits like a truck and the chainsword has the "shredder" alternate attack to help with big specials if they get close and I'm out of ammo. Lots of ammo is helpful and teams regularly recognize that the bolter needs to be kept fed to be useful so they tend to defer pickups to those who use them. If you're not a bolter and or chainsword fan then I'd suggest using a headhunter autogun and a power sword or something else with a good high percentage in cleave to sweep away crowds should they get close.
Activate Volley Fire as much as possible, it's incredibly helpful to see what's coming and track specials when you hear their call-outs.
Remember, you can dodge. Doing so is easier in Darktide than it ever was in Vermintide.
Let's Look At The Build I Used
Feat One - At Arm's Length
At Arm's Length is very useful at keeping your toughness up while you're at range. Remember that it's okay to take ranged damage during this penance but not melee, so staying back will help. However, if you are hit at range you want that toughness bar to refill quickly. If you go down then you're vulnerable to melee damage. Stay against a wall or protective surface to cover as much of your blind spot as possible because if you're at the rear you're the first target for a group coming from behind. Make sure to pay attention to the doors and ledges that hordes can spawn from, you don't want to get caught up in a bad spot in any situation, certainly not during this challenge.
Feat Two - Sniper
Sniper will keep you useful to your team while you're staying out of harms way as much as you can. It's important to have an accurate weapon for this penance. The bolter is what I used because it's quite accurate in single fire mode and for lots of enemies you'll only need one or two shots before you move to the next target. The hellbore lasgun is also good for attempting "On Overwatch", but it uses large chunks of ammo to get the charged shots off. I'd suggest a headhunter autogun if you don't like the bolter. Even better if you manage to get one that is single shot because you'll have a lot more control over your ammo pool.
Feat Three - Covering Fire
This build isn't very efficient as a daily driver but Covering Fire will give your teammates some much needed support while you're helping clear the chaff. It's effect works on all enemy types so snipe away and feel good that every dreg, scab and groaner you drop is helping keep your group's toughness up while they keep you from becoming a target. Especially helpful in crowds, Covering Fire can actually turn the tide in those tense spots at the end of missions while you wait for the exfiltration point to open.
Feat Four - Camo Expert
Recall how I said to stay against a wall or surface to help keep you protected? Camo Expert really works well with that because finding a good spot to park yourself is rarely helpful when you can't stay parked. I've actually had ragers and maulers just run right on by me from the back because I'm more or less invisible to them while I'm standing in a corner. It's even more satisfying when you can give them a little lead and then snipe them away from your teammates. Don't get too complacent though, it's not foolproof. Stay alert or fail the challenge... and the Emperor.
Feat Five - One After Another
This one comes in handy when using a weapon that is slow to reload for sure, but in general it just gets you back in the fight quicker when you run out of ammo. One After Another is sort of a lynch-pin feat because it sort of ties everything you've got so far together. Stand still while elites run by - tap Volley Fire to highlight them - pick them off and keep your group toughness up while simultaneously speeding up your reload time. This really makes you a valuable member of the group. Not to mention if you get cornered you'll probably be able to unload into the crowd and put down a shotgunner or trapper or something that will help you reload quicker thus making you less likely to take that one melee hit that fails the penance.
Feat Six - Counterfire
This is why you want level 30 before you really try "On Overwatch". It's possible you could get it done before you have access, but Counterfire will allow you to use Volley Fire to it's fullest while in the current build. And you should use Volley Fire as often as you can. It's especially helpful for tracking bursters, hounds and mutants, who all count as melee damagers and will thus ruin your shot at completion really fast if given the chance. Once you hear that ticking, those claws clamoring, that mutant tromping - hit "F" and focus them down or at least be more ready to dodge out of the way. Volley Fire will also now refresh the very quick to end base duration with every highlighted target you deck, and you'll be surprised how many targets get highlighted. Worth noting is also the fact that your whole team can see those highlighted targets so it's good for everyone. The additional weak spot damage is frankly just icing on the cake.
Hang In There
The problem with these harder challenges is that they force people to play sub-optimally and that's not a great way to go as far as I'm concerned. Even with this build you're probably going to spend quite a long time trying to make this penance happen. I think it took me something like 52 attempts and I finally finished it in a random group.
If you can help it, just try and stay with everyone and move deliberately. Clear a space and move forward. Don't get over-eager. Keep yourself protected. Stay alert and support your team. People are much more willing to help you if you're helping them as well. Say something at the mission start about your intentions. You may be trying something at the same time as someone else and that can work in your favor.
Be ready to just bail on the challenge at any point. If your group is going down and you can still pull out a win by risking a hit while picking someone up, do it. You may not get hit after all, and failing a mission doesn't complete the challenge anyway. And don't be a leaver because you took a hit. It's not good form.
It's going to take a lot of tries but here's hoping this build and my own humble tips help you to get it done. Some of these tougher penances are probably going to happen organically, "On Overwatch" is not one of those. You have to be vigilant and intentional at all times because a single melee hit from any enemy in the potentially thousands you'll see in a single mission will stop your progress as long as you take damage. Nothing is more frustrating than making it to the end and being hit by some groaner just as the door to the exit to opens up. It's going to happen. Stay with it and you'll get there. If you have a full group of four friends, even better. Communication is better and they're more likely to help out because you'll be down to help them as well. The thing to look forward to is the sense of accomplishment once you do finally tick it off. That new chest piece looks cool with the seal on the shoulder. For me and probably most of you it was also the last step in getting "On Target 2" completed. Luckily the third step up doesn't appear nearly as hard to attain.
Good luck to you.