Classes that have to do with memories or dreams?

[Sasori]

Really weird question but just wondering a class that can do something with the foes dreams or memories thanks srry for the weird question lol

[Tegu8788]

That would be a ritual almost certainly. That kinda thing isn't class powers in 4E.

[NecroRebel]

Things that were fluffed as memory or dream alteration would probably be psychic damage, with some radiant. You could fairly easily refluff many of a feylock's attack powers as simply causing the foe to forget who they are, for instance, with them ultimately forgetting who they are enough that they simply don't remember that they're supposed to be alive. Quite a number of wizard illusion powers are already fluffed as nightmarish, so they'd be easy to make fit your question as well. Any psychic damage could fit, really.

[Mando Knight]

Things that were fluffed as memory or dream alteration would probably be psychic damage, with some radiant. You could fairly easily refluff many of a feylock's attack powers as simply causing the foe to forget who they are, for instance, with them ultimately forgetting who they are enough that they simply don't remember that they're supposed to be alive. Quite a number of wizard illusion powers are already fluffed as nightmarish, so they'd be easy to make fit your question as well. Any psychic damage could fit, really.

There is the psion, which specializes in psychic combat...

[Cloud]

I agree most of what you're after is likely ritual stuff, but a Fey Pact Warlock or a Telepath Psion might fit the build too. Might need a little refluffing but not too much, use a warlock power that makes you invisible? Doesn't so much make you invisible as just the enemies forget you, etc. If nothing else the Psion gets the appropriately named Dreamwalker paragon path.

[GPuzzle]

There's also the Nightmare Weaver Paragon Path for Warlock characters trained in Intimidate.

[Sol]

There's no mechanics that deal with dreams or memories, really, so you're entirely dealing with fluff here.

In addition to the obvious Psion, illusionist wizard, and fey lock, you're free to come up with your own explanation for how any powerset accomplishes any objective. Maybe you have a githyanki silver weapon and flavor its psychic damage as slicing through your enemy's dreams.

Also take a look at the wizard utility 2 Memory to Mist and the bluff utility 6 Faulty Memory.