((Okay, so if I get serious in this designing step...
Stat drain would apply to each skill/attribute rolled that round, with the exception of complex actions and defensive rolls. Defensive rolls have a ~25% to trigger the effect, and complex rolls have a 50% chance to trigger per roll. Targets could immediately reverse stat drain at twice the normal rate by taking a essentially skipping a round. If the effect completely drains an attribute, each point of skill/attribute lost will 'detonate'. Target will take take 5 of stamina damage for each attribute detonated, and 3 points for each skill point detonated, but the target will regenerate all points lost that particular attribute tree points over the next two rounds. Against psychic targets, all stamina drained will then immediately be used to fire a standard a -3 neural feedback using your P.Empathetics a roll. Non-psychic targets will take health damage equal to the stamina damage. Sound good? Difficulty will probably modify duration, and, to a lesser extent, damage.
-> An attribute hits 0, Evolved attack detonates and devolves -> free neural feedback against psychics/health damage against others
So. Use Ability->Stat Drain->OR
-> Effect Duration runs out
On an unrelated note, I started listening to BÖC while writing. First song that came up? Veteran of the Psychic Wars.
Also, I'm coming to the conclusion that I actually do need to revise how stats and skills work. My optimism when I switched to a d22 was, perhaps, misplaced. Je suis la grenouille.))