By the times of Dark Empire, the Emperor spent many years secluded on Byss, training extensively under Jedi and Sith holocrons that he had abducted from various Force-strong planets. His Force powers have been immensely upgraded, to the point where he developed a new ability (The Force Storm) that is capable of destroying anything it comes in contact with.
Sidious is also in a youthful body, with above average reflexes, as well as his even stronger attunement to the Force.
Yes, well that may be simply because you confessionally detest Sidious. People have been indoctrinated that the Ancient Siths ought to be all powerful and Force Gods themselves. Personally, I see no reason why anyone - Sidious included - should have the power to chuck stars or fling Star Destroyers into space. It bothers me. How can such beings be defeated? All people should have weaknesses, especially in movies. Weaknesses make a character 3D.
Registered: Feb 2005
Location: Hiding from zombies
Darth Somebody said a similar thing months ago. But what he doesn't realize and perhaps you don't is that said Force gods always have glaring weaknesses.
Marka Ragnos was content.
Nihilus was unable to feed on the Exile.
Naga Sadow was undone by his own minions.
Exar Kun was forced into hibernation because of the jedi forces.
Even Freedan Nadd, for all his supposed power, had a relatively uneventful life aside from the capture of Onderon. Such "force gods" don't run around beating everyone. At least, not in the EU continuity. In the Versus Threads, they tend to pwn without mercy.
It's plot device, Escape. Thematically, they are supposed to be that powerful. It's that old fairy-tale evil never wins idea. Despite all the infinite power of these Dark Side titans, they still end up either dead or floating around as ionized air particles. Great fate, isn't it?
Perhaps so. But that power is grossly exaggerated. The ability to chuck a STAR. Doesn't that seem more than a bit overpowered? Now, if it were a house or something, maybe. But an entire STAR?
If they have to possess it, I see no reason why Sidious or Luke ought not have these powers. Sidious got killed, eventually. And Luke just needs his ass beat.
A house is hardly impressive. Chucking around a Star would definitely give the impression they are force gods. However, they still were unable to conquer the republic, simply because there are millions of stars, and millions of systems, it's not a place a single individual can take by force.
For that matter, they are really only overpowered for game or versus purposes.