You could use confinement, or try to outdamage his heal with the shadow pyscho's epiphany combo.
On challenging, I managed to reduce his roach vitality to about...3 hp a turn. Roald slowly withered him away, while Veradux healed. When his roach vitality runs out, use retrograde, in case he full heals. Procede again, if he doesn't heal.
Eventually your dark echos (if you use them) and roald's attacks will kill him.
Confinement produces a pretty large heal reduction.
Another way is to have overdrive, and use shock coma on him when he has roach vitality on, and then use a lot of high voltages. When you stack enough of the effects on him, use retrograde. He should klil himselfl by healing, then taking more than his life.
errr psychos dont have disrupt.. kindly read the subject.. and besides you said you dont even prefer bios, you said you like hydros and psychos.. then "disrupt spam will own ALL".. errr ironic?!
oh yeah and thanks for the tip guys, im tryin to start a heroic run for psycho..
You could also keep traumatizing him and attacking him between traumatizes to keep his focus down. He's going to be stuneed half the time and the other half, he won't have focus (at level 2, it drains 15 focus every turn for two turns).