If you have Mid's hero builder you can see what sets available and can pick up somethings you like.
I was using Nightmare on Terrify but will change it with Glimpse of Abyss (which is highest one in fear sets). Only thing you must think is Essence of Curare (that one is little tricky, some level recipes are bugged. If you read the description you can overcome this handicap tho)
I usually kept two things in mind with Psy-knight; +dmg and +acc ones. But as your hero is a Mind/FF you maybe want to consider +recharge ones too (which is covered by Hasten/AM on Psy-knight).
I also slotted Mesmerize with ranged damage set (iirc Ruin) but will change it to Thunderous Strike if i find time.
Guys, what do you think they are the best enh. sets for a lvl 50 MC/FF troller