Make a level perks that you can pick one of that give brain burst extra abilities.
Interesting ones would ones that give you utility.
BB goes off as well as the utility effect
My ideas are
fire lightings that stun in a AOE
Warp fire explosion that’s like a fire nade but smaller and shorter than the fire nade the bomber throws.
Small aoe explosion that throws the enemy to the ground rag dolling them. Works on ogryns.
When you BB a second BB channelled on the same target channels 3 times as fast and gives 50% less WP. (Most boring but probability the best tbh)
Mind control (two options.)
1 You channel brain burst on a target and while channeling they frenzy and attack everything around them and friendly fire down stuff and when your BB goes off they die or continue to frenzie for 3 more seconds if they live.
2 You channel BB on a target and once it goes off they are frenzied for 5-10 seconds and at the end BB goes off.