heres some ideas i thought of as i was trying to see how well wrack and ruin can do and ultimatly i found it did have some good enough purpose to make it so the time spent Brain Bursting wasnt resulting in a total lack of time spent taking out hordes. personally i feel it still has to specific of requirements to really be useful over the other 2 traits in its line since the ones its next to is warp unleashed which is a flat 10% bonus dmg up to 25% dmg as you go up in peril and good psykers can dance that line easy and have crticial peril all the time and inner tranquility is a bonus 6% peril resistance per warp charge which is so f*cking nice for letting you use your warp abilites more especially on the surge staff.
all in all it really just doesnt stack up to those two and what i think could serve as a good way to make it more useful is to do two things which also would require some other traits to change a bit to not be too op in combination but still i think at BARE MINIMUM it needs to have the specialists and elites requirement removed and that should instead be given to kinnetic flayer so YOU KNOW that trait is gonna do some nice sh*t if your using a purgatus or surge staff or something like the recon lasgun with the second change would be to give it also a flat bonus 25% BB speed.
now those changes would make wrack and ruin and kinnetic barrage busted hence why kinnetic barrage would likely need to have i think the speed boost reduced but the bonus peril resitance could stay and maybe it could still keep a bonus 25% after it pops so you still can have that max 50% BB speed. personally i feel that alone would already make BB builds that focus on it so much more viable especially with a purgatus and kinnetic flayer as you spam out flames towards any big targets while than swapping back to BB to pop every f*ck you see.
lastly i also think the brain burst skill needs a total rework but imma make that change in its own post since this one is already too bloated with run on sentances cause i hate writing XD