Problematic Powers 2: Dream Control
When this power shows up in my rolled-up characters, my hope is that I can trade Dream Control for an Extra on something else.
Not because Dream Control isn't a cool power, or that I think that it shouldn't be there. Dr. Destiny has Dream Control, and the issues of Sandman where he appears are fearsome. He has a slightly different flavour of Dream Control than is in the ICONS rulebook, but it's pretty definitely Dream Control.
Here, this is what Dream Control is, according to the ICONS: Assembled Edition rulebook.
Dream Control is the ability to manipulate dreams. You can control your own dreams, choosing what you dream. More importantly, you can implant images into the mind of a sleeping individual, like the Illusion power, but rangeless.
Part of the problem, for me, is that Dream Control is a weirdly delayed power, not conducive to a lot of games. The power wielder enters the minds of sleeping individuals and can implant images. Useful if you have to get help and they don't know about the power, but not exactly something that makes for dramatic action:
"If only Deus Mex Anima knew where we are!"
"I'll put an image in his sleeping mind."
"You've been to his house?"
"We had a sleepover there once. You couldn't come; you're a girl and have cooties."
So it's not that I think it's not a valid power, but rather that I think it's not a particularly interesting power as normally used by players. I don't recall Dream Girl doing much with it: as I dimly recall from my Legion-reading days, she was mostly about the precognition. Dream Control for players (not villains) is used for psychotherapy. It's a utility power.
Maybe the ability to control your own dreams is the key part. We invent some way for the villain to enter your sleeping mind, and the villain is trapped there. Some people use Telepathy for this (the battle between Psimon and Miss Martian on Young Justice is clearly a telepathic battle), but you could use Dream Control in the same way.
The hard part would be getting the opponents there.
Maybe you could have a Teleport that's thematically an Alteration ray: instead of phasing you or turning you invisible, it puts you in his head, or the Dream Realm. They get to act "normally" (given where they are) for the first panel because you're suffering from teleport shock. In my reading of ICONS and Great Power, there isn't an Extra that makes Teleport offensive, so it's thematically part of Alteration Ray, but get your GM's approval.
When heroes have it, it seems to me like either it's a secondary power ("MindMan can read minds, send tremendous blasts of mental energy, fly, and control dreams") or it's the whole point of the adventure. Characters trapped in some other person's head can use Dream Control to change the dreamstuff around them, or characters who have ventured into the aboriginal Dreamtime have unusual facilities that will help them control their environment.
I suppose you could also do a campaign like a superhero campaign, where the heroes venture into a head every week. In that realm, they're superheroes, but everyone has some degree of Dream Control. It would be risky to run because you don't want to make light of people with actual mental problems, but it might be a short campaign about dealing with the mental parasites from Dimension Xarg. Every week a new victim is brought in, but one of the powers these parasites have is to make the subject immune to sleep: they've walled off the subject's dream realm. There's a time limit to how long they can make the subject sleep. The heroes have to go in, and defeat the aliens. As the campaign progresses, they get to people who have been possessed longer, and their dream realms have been turned into factories for these parasites and the "tools" they use.
Not as useful an ending as the discussion of Aquatic, but I hope it has sparked some ideas for you.