from the very minimal i have played with mental i think its mass terror but im a serious rookie (when it comes to mental) so dont take my word for it
Probably mass terror and phantom flames??? (someone who trolls often with Mental can correct me) Mass Levitation as well, but its a time cast move so probably not. Didn't really troll with mental when I was it awhile back and going through the hoops now again.
Horrific Visage will be able to polymorph numerous enemies clumped together. I don't know if there's a limit or not. Mass Terror stuns up to 5 opponents at a time. Mass Levitation levitates up to 8 opponents at a time. Levitation tends to end immediately when they get knocked down though Fortunately, Mass Levitation also dazes opponents, making Cryokinesis able to knock down up to 4 opponents at a time Terror Tendrils stuns up to whatever number of opponents, as long as they hit them. Pyrokinesis can stun everyone if it explodes an encasement Telekinetic Bolt knocks back and stuns up to 4 opponents at a time. Most of the other powers control up to 2 opponents at a time.
My favorites for Crowd Control are and forever will be Mass Terror (panics and stuns up to 8 targets) and Terror Tendrils (stuns whatever it touches)
There is only one thing I miss about mental, the ability to ghost. Horrific Visage is amazing PVE CC.
Mass terror "works" the best but also uses far now power then the others so IMO it is not the best for crowd control Tendrils works decent and much less power
I would definitely recommend the thought bubble/pyrokinesis power interaction for crowd control. Not only is it relatively efficient regarding power consumption but it also causes a bit of damage to a single target and causes the "burning" control effect to an enormous AOE. The two powers involved are also debuffs which is something trolls are expected to have anyways. Also, since thought bubble encases up to 2 targets, you can get twice the bang for your buck if you are positioned correctly. Just line up the bubbles and fire pyrokinesis at the further bubble. If the pyrokinesis beam passes through both bubbles, bingo!
The area is massive. Also, it's not a PBAoE, apparently. It looks like it is, but it works like Phantom Flames with a bigger AoE.