No, it is not. Invoke panic is a mag 2 (only affects minions) 10.43 second fear (at level 50) with a sixty second recharge, low base accuracy, and a hefty endurance cost. Even if you were able to double the duration of the fear, half the recharge, and half the endurance cost with slotting you would still be left with a non-perma minion fear with no to hit debuff. Arguably one of the most terrible powers in the game, up there with temperature protection. Srsly don't take it.
I ran this for a while on my ninja/poison and it's pretty much bunk for the above stated reasons.
If there's enough minions that this might matter, then you're probably running around making sure the pets aren't dying. If the pets are fine then there probably isn't enough minions to ever care.
Oppressive gloom is pretty much better than invoke panic in every imaginable way.
Thanks for the feedback I've only been back for about a month or so and alot has changed since the last time i played 
Invoke Panic will invoke panic on your build.
Depends on how many free spots u can spare. Oppressive gloom is indeed impressive for a single power pick, but the aoe taunt in the presence pool can be incredibly useful for a mastermind, especially on a pain where your secondary is about responding to damage after its happened (though getting mez protection or resist would be vital to using it). And if u use invoke panic among a lot of minions and then use the ST fear on a boss, u have both the minions out of the picture and the boss in fear for a while as well. But it does all cost a lot of endurance, and the ST fear is wretched, possibly being one of the worst moves in the game on its own, because it only affects minions and its other stats like endurance use are horrible. But I had fun with it on my Nin/pain, and it's worthwhileness might have shown more if my tier 1 pets weren't made of paper.
Hey all I'm in the higher levels of my thugs/pain and was looking for some sort of crowd control. I know i can get an aoe immobilize with the anc pools but if I can squeeze it in is this power worth it?