Ryujin
Legend
Funny how dazing and immobilizing actually work wonders in preventing enemies from going and doing whatever it is they want to do.
If there's a brute, and I immobilize him five squares away from the party, great news, he's out of the fight completely. He isn't running around back to flank or charging the leader. If used properly, immobilize does EXACTLY what I describe.
Dazed is very similiar, when used properly, it does exactly what I describe. Daze a foe, everyone moves one square out, and the enemy can move a square or do nothing. That monster is out of the fight.
It's not the specific effects controllers get, it's their ability to leverage them that other roles don't have.
It's for this reason, that I sometimes refer to the Feylock as a single target Controller. My Fey/Darklock combo was pretty good at the role. There was quite a variety of things I could do.
"Why are you hitting the air?"
"Why are you hitting your buddy?"
"Why are you hitting yourself?"
"What are you doing over there, 30 feet in the air?"
"Launch necrotic smoke ring #1. Buh-bye minions."
"Launch bigger necrotic smoke ring #2. Buh-bye Soldiers."
"Go away for a little while, won't you? Another plane of existence would be nice."
"Take some damage. Now get away from me, or take a whole bunch more. Go away son, ya bother me."
"Go over there and take a whole bunch of damage."
"You might want to think twice about hitting me 'cause 10 of your cursed buddies just dropped, and hitting me is REALLY gonna hurt

And that's pretty much how I played my "Faceless" Eladrin Warlock; flippant and dismissive, when he bothered to talk at all.
Some of the classes not only share the abilities of other classes, but really blur the edges of the roles.