So i want to give my opinion on the Psyker Force Weapon Mastery Perk.
First of all: I really do like this one, even tho the Psyker don't have as many different weapons as the other classes to utilize that Perk he still have more than enough for everybody and every situation.
I really like this one because this is a really "playstyle" defining Perk, it makes the pace of combat a lot faster because to make good use of it you have to go quickly between groups.
But i do have some dislikes with this.
The first thing is that it makes the gameplay almost a bit too hectic/stressful because you feel like you are on a constant run to not lose the stacks.
The second thing is that you can gain stack/refresh the buff by casting any Weapon skill without hitting anything. So if you want to make everything out of this you have to constantly cast even while there are no enemies around, so you don't lose the stacks and have to rebuild them.
In my humble opinion there are several ways to make this perk feel better without destroying its "gameplay defining nature".
First: Make the maximum Stacks a bit lower(lets say 5). So if you lose it it don't take so long to rebuild them. You can probably buff the dmg increase per stack a bit then to compensate(e.g. 20-30% per stack)
Second: Increase the duration of the Stacks(to maybe 8-10 seconds)
Third: Remove the ability to gain/refresh stacks by casting Weapon attacks into nothing, without hitting anything(this one is especially important for me, because if you cant do that anymore you don't feel to "lose" anything if you not cast constantly out of combat, which makes the gameplay a lot unnecessary "clunky")
Any combination of those 3 ways combined in any amount(numbers are of course to be tweaked) would help this Perk become a lot more "enjoyable"
Feel free to give your own opinion or suggestions.
The Emperor protects!