It’s not magic, it’s the warp.
The "Assail" Blitz is an incredible ability that deletes any unarmoured enemy in the game. Any staff other than the Purgatus staff work great with this blitz. The only thing the blitz can't handle is armour, so you want a staff that can do that. I've chosen to use the Trauma staff because I like it, but literally any staff will work here. This build potentially the best build in the game because it removes the loot RNG from the game, as you are using the blitz ability 90% or more of the time.
If you pop gaze and then quell some of it with headpop, you can reach insane damage output with your guns. This makes Veterans guns look like they are nerf guns. I pair it with the dueling sword, as you will often hit 100% peril, so force swords are dangerous. The high crit chance that you are given combined with "Empathic Evasion" allow the blessings on the dueling swords an excelent uptime.
I prefer the double walls over the dome as you can spam far more of them, and their ability to block all specials can come in clutch preventing untimely pox bursters or mutants from reaching your allies. Any staff works with this build. I went with Purgatus because it spreads wildfire like crazy and it's enjoyable watching the heretics burn while hanging out behind a shield.
UNLIMITED POWER! simulator. This build provides your entire team with insane crowd control. The "Smite" Blitz provides better crowd control than any other ability in the game. I would argue it is ever better than the Ogryn Taunt because of the decent range. It can grab a giant group of enemies and make them stand helpless as your team strikes them down. I like to pair it with the Surge Staff because the only thing better than lightning is even more lightning. The Surge Staff also deals with armour pretty well, so it pairs well with the dueling swords.
The "Assail" Blitz is the most powerful blitz in the game currently. It is very strong, and can carry most games by itself, without having to use any of your weapons. Headpop is still great if you use the Purgatus staff so you get range, and Smite is the best crowd control ability in the game. Once Assail gets nerfed to be more inline you can't go wrong with any of the Blitz abilities on the Psyker.'
One Health, One Toughness, and one Wound are probably best on the Psyker. The Psker is squishy in both Toughness and Health, so having more of each ability is useful. The wound is also a good option to help cover for accidental explosions as well as times you go down to a sneaky enemy hitting through your paper defenses. If you don't want to bring the wound going either more toughness or Stamina is always good. Stamina combined with "Kinetec Deflection" and "Deflector" gives you crazy survivability.