As on last night SG, it made it very clear Imps use real magic, not super science!

Magic.

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So how can they be stripped or blocked accessing their powers, as should be right up there with top powers in entire DCU?

In that one show and perhaps early appearances but the overwhelming history says it is super advanced science. I am not current
on-well pretty much all comics- so maybe things are not the same.

Or maybe their science and tech is so advanced to us appears as being Magical in nature? Think existing in 5 Dimensions means they would have extraordinary powers compared to us either way!

That is the way I have always read it that way.

So would be similar to say the Beyonders over in Marvel, except Imps exist outside linear time?

If they simply inhabit a '5th Dimension', then they can't exist outside of our time and space.

A fifth dimension isn't somewhere else cut off from our universe. It's an intrinsic part of it. It's just another direction.

they would be existing outside of our time and space though!

What? No.

We perceive spacetime to have four dimensions. They're basically four directions.

Up and down. Let's call that the 1st dimension.

Side to side. The 2nd dimension.

Forwards and backwards. The 3rd dimension.

Time. The 4th dimension. This is the only dimension we know of where the direction is limited to one way.

So what's the 5th dimension? It's just another direction. One we don't perceive. It's not a direction we can point to (But that's no biggie - We can't point backwards or forwards in the 'time' dimension either).

Quantum mechanics tells us our universe, our spacetime must be made up of somewhere around 11 to 15 dimensions. Fifteen different directions.

But none of them exist outside our spacetime. They're all within it, and part of it.

Where does it say magic users cannot be stripped of their powers or have them blocked?

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Mxy and his like have been shown able to over power even the Spectre before, so would take top levels to do that!

So his magic abilities can be blocked or stripped. As for the incidents with the Spectre, you recall that the Spectre's abilities vary depending on circumstances? That the Spectre was lessened in power after the first Crisis, as well? Sounds like you've been deep-diving on the battle boards: all scans and little substance.

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The Imps though have always been shown as being right near the top of the DCU power food chain!

Sure, but even Mxyzptlk has limitations, inasmuch that Superboy and Superman were able to defeat him, using only their wits.

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Mxy like original Beyonder, both nearly all powerful, but not the brightest light bulbs!