Good combo for psychos: Use retrograde an on ally, then betrayal. You heal you and your ally by 100%, and you get a boost.
A good attack strategy for psychos is 3/3 shock theraphy and 3/3 electrical storm. Use shock and when you are low on focus use electrical storm.
How to do the withdrawl combo with Bio:
Respec and choose equipment so you have the highest speed possible. Get 3/3 Crystallize, 4/4 Withdrawl, 4/4 Shadow Blend and 3/3 Agile Exposure and 1/1 Toxicant form.
Do Crystallize on the enemy (So he can't do anything while you prepare his doom), Toxicant form, shadow blend, Agile exposure, Withdrawl.
Depending on stats and equipment, at the end of the game you'll hit between 25000 and 40000 with this combo.
My record was 126000, but that was due to Orb of restraint's flawed design (Zone 7)
Bound, Veradux's healing scales with his Instinct. Also both classes are equal, but psycho has more stable moves, but bio has better ones.
With speed bio I can easily hit 30000 with withdrawl.