You may have missed Unlocked and Loaded, there were noticeable changes made to Psyker in that update. Right side, Crit build Psyker is now stronger than ever and probably the most survivable in higher difficulty content. (Excluding Havoc because I don’t do Havoc).
Here’s a build that does a good job of improving melee, not much forgiveness for mistakes though the stagger on Catachan may make combat safer than other melee options.
For a more versatile and survivable approach, going down the right side frees up Talent allocation to be spent on One With The Warp, Malefic Momentum, Perfect Timing and Warp Splitting for excellent horde cleave as well as those spicy insta kill Electro zaps on Specialists, periodically when all the right buffs are active.
Feel free to swap Savage Sweep for Rampage or Skullcrusher if going down the right side, as the extra cleave isn’t needed as much with Warp Splitting/Assail.
Like so:
