Having worked as a farmer and woodcutter for most of my life i became determined to do something that would leave my mark after i was gone. Since then i got back to studies, and i have now a master degree in Electrotecnical Engineering as well as a degree on Electromechanical Engineering. On my free time i like playing and so i became interested in creating my own games or, in the shorter term, modding games to get something closer to what i would like games to be.
Not all psykers among chaos/renegade armies are former imperial psykers, in fact if most commissars do their job well almost no IG psyker would live long enough to become a full follower of chaos (some commissars have an itchy trigger finger when around psykers) and so cultists, traitor guardsmen and overall renegades and the likes will likely also be psykers in some situations (the Imperium does not know every single psyker in the galaxy and some cultists and renegades never lived inside the Imperium's borders).
Have you thought of changing the las fire fx into a psychic fire fx?
If it is bloat you are worried about, remember you can always Xref a whm/whe.
With the las firing changed.
I got bad lag, Im out.
All anims of the evil_chaos_psyker I used as a base for this are Xref'ed to the sanctioned psyker so no issue with whm sizes.
The change of the fx can be done and would actually be helpful due to allowing an additional swappable object.
Lightning, plasma ball or D-cannon?
Lightning would probably be the best in my opinion although your other options and also the horror's projectiles would also be interesting options.