I can kill anything instantly and revive the entire team.
 Veteran Build - Warhammer 40k: Darktide 

Build objectives:

1. Basically you have the ability to kill any potential threat such as a "Trapper", "Flame", "Crusher", etc. in 0.3 seconds with our revolver, in the middle of a horde. You will have a guaranteed critical and absolute precision. Also you don't even need to recharge manually, "Always prepared" does it for you.

2. While using the knife, we always have to dodge. We will be a machine gun capable of quickly killing regular enemies and they will not even touch us, even if there are 50 of them. You can also randomly shoot an enemy to activate "Weapons Specialis", we will become a minigun for 10 seconds, striking everything except "maulers" and "crusher", these are better to shoot quickly, due to their great danger.

3. In case of a fallen ally we can approach it, avoiding enemies with our absurd mobility and use "Stealth" to revive it, while they kick it to the ground.

3. In case of maximum emergency, you can run out and dodge everything until you run out of stamina, and then use the 2 "Stealth" to revive your team members in the lobby, possibly recovering a lost game.

Special enemies:

We must always carry the knife in hand and take out the revolver only when we are going to shoot a special one.
With this we activate the 33% critical chance of "Weapons Specialist" and it will be a guaranteed critical for the face, allowing us to kill instantly with a headshot.

We can also kill gunners or anything that shoots at us quickly, because we are immune to the suppression of their shots.

Normally you will only need a one or two headshot :

Any elite or expert enemy:
- 1 headshot
Crusher:
- 2 headshots
Scab Mauler:
- 2 headshots
reaper:
- 3/4 headshots
Bulwark:
- 3/4 shots to the head (difficult to hit with the shield, better to hit with melee)

Bosses:

The bosses are not spared from our destructive power either.
We should save all the grenades for them.
With 3 grenades, we can reduce the life of an easy boss by half, in the following way.
Grenade --> (stunned boss)3 Melee Hits --> Grenade --> (stunned boss)3 Melee Hits... until we run out of all the grenades, then dodge and hit melee
Our knife applies bleeding and has an advantage over bosses, you do much more damage with a knife than by shooting them. So it's better to hit them with melee and save the bullets for the annoying "specials".

Conclusion:

You are a killing machine capable of doing the work of 2 or 3 people.
You can clear hordes and kill specials very quickly and easily, without taking damage.
You can lower half of a boss's health on your own quickly.
You can comfortably lift your teammates or revive an entire team if necessary.

With this build it doesn't matter if you have a team of one-handed people, you can do their job and revive them, if necessary.

I didn't want to focus on explaining how each key "advantage" works, it would be too tedious.
Simply explain the consequences of combining all the advantages and the mechanics that have to be used.