I did this for my legend run with a level 19 psychotic. I respeced my guy for full shock coma, full salvation so veradux could heal 2000 hp a turn, and then full damage (shock therapy, electrical storm, wraith form, charged blood). The strategy's pretty simple- keep veradux on salvation & healing and concentrate on the enemies one at a time.
At the start, keep one riot police in a coma at all times and concentrate on the other riot police; the android guard doesn't do too much damage. The first riot police should die within 2-3 wraith form rounds. I was a little careless; at this point Roald died.
Next, keep the android guard under coma and pound on the next riot police; should die pretty quick as well. Then do this for the android guard. Don't be upset if you can't break through the android guard's shield at the end; just keep pounding on him. Eventually, he'll run out of focus and stun himself to recuperate his focus; this is where you can do the damage to him. 1-2 wraith form rounds and he's done.
As for me I used the speed bio with withdrawl on the legend run. first move is to crystallize (3/3) one of the riot police. Then proceed to buff up and attack the other riot police ( I used Toxicant form, then shadow blend, then agile exposure(or one move of slash), and then withdrawl -- e sure that withdrawl is the last move you use while under the toxicant and shadow, this way you recover extra focus for the next two turns). At this point I would cast Crystallize on the riot police who had been previously crystallized. And then I cast another crystallize on the Android guard (place 2 crystallize on your move bar). Repeat this until the un-crystallized police id dead. Then only crystallize the guard. Veredux on phalanx. And roald on relentless (sometimes you might have to put him on phalanx so that he casts his healing-enhancing ability).
If you are not doing the legend run, then you might want to train. In addition you should get that footware in the shop that gives +41 to vitality, and the law binder, which also gives +41 vitality. That should be enough to keep him alive.