Psychic Veteran
 Psyker Build - Warhammer 40k: Darktide 

The theme of this build is to represent a warp gifted soldier. This is a support - jack of all trade build allowing you to protect your team using your bubble, snipe priority targets with your lasgun, kill carapace with your uncanny strike deimos sword (I find that spamming light 1 - heavy 2 while aiming for the head works well) and clear hordes / patrol with your spam assail.

Gameplay loop is pretty straighforward: spam assail until max peril, swap to sword or lasgun depending on the situation, kill a bunch of stuff, rince and repeat. 

You have a pretty good mobility thanks to your movement speed on crit and good survivability thanks to your shield and +60 toughness nodes, giving this build pretty good clutch potential.

The main weakness of this build is damage versus monstrosities, for which assail is pretty crap so you're pretty much left with trying to spam headshot with your rifle and speacial attacks with your sword. So when monsters arrive do try to focus the adds to keep your friends free to kill the big one safely.

Regarding the choice of lasgun: this is mainly a thematic choice, the idea of the build being to represent a psychic soldier. However, the lasgun allows you to headshot kill priority targets very quickly and combos very nicely with Disrupt Destiny. Lastly, as a psycher, you're pretty much the last one entitled to pick up ammo. The amazing ammo efficiency of this weapon allows you to leave ammo pickups to your teammates and only grab those they leave behind.