No, Sidious can't destroy planets, and not many can. But, remember the thread title...we're still talking about ALL Jedi, including one who can (Exar Kun).
Well now see, I wonder about that. I don't know much about Exar Kun at all, in fact, but I DO know a little bit about how character abilities get overblown (Batman is perhaps the worst offender, but there are plenty of others). So I did a check on the Star Wars Databank about him, and all I saw about planet-destroying was this phrase: "His followers triggered ancient technologies that detonated the stars of the Cron Cluster, wiping out entire worlds and searing the surface of Ossus."
Is that what you mean? Because the way you describe it, it sounds like he just glared at a planet and made it go "boom" ... but then if he could do that, why would he need his followers to "trigger ancient technologies"?
Sounds to me a lot like he needed his own version of a Death Star ...
Here we get into some power discussions. The Jedi can pull him down with TK, and even if it is low-to-mid level TK, multiply it by thousands (probably tens of thousands) and you've got a force (pun intended) that will keep Magneto grounded.
Maybe ... maybe not. It's difficult to quantify this exactly, but it's theoretically possible. Of course, since they can't all be attacking him this way at once (line of sight!), he could still rip apart the front lines and then duck away again as the TK holding him down vanishes. Too many people at once can actually hinder each other as much as help. It becomes one big friggin' Charlie Foxtrot ... especially with whirlwinds of metal death spinning through the ranks like giant lawnmowers ...
Same deal. First it assumes that there'll be metal around
Why wouldn't there be? There's at least trace metal almost anywhere you happen to be. There's iron in your BLOOD, and that's all Mags needs. It's not like he needs a construction site to get enough metal to work with.
and also that the Jedi can't resist it.
Resist it how? When the most powerful among them are barely low-end telekinetics and most of them aren't even remotely THAT powerful?
Will Mags pull some lightsabers away and kill some Jedi with nails and whatever else is around?? Yes, of course. But will he kill all of them before the Jedi mount an assault?? Not even close. If all the Jedi have to do is block a few nails from hitting them
... and the iron from being stripped from their blood, and their own sabers from being swung at them, and all trace metals in the area surging up to attack them ... etc. ...
none of them will be dying that quickly
Most of them will be mere cannon fodder. The only ones we've even named are Yoda, Sidious, Luke and Exar, and those are WAAAAY beyond normal jedi levels.
...and even Mags doesn't have enough power to rip thousands of lightsabers away from trained telekinetics.
Well, that may be. It's hard to say.
The reason I decided Mags would win is because unlike the jedi, he has the ability to enter or exit the battlefield at will. He has mobility ... and that counts for a LOT. And it's been mentioned, too, that if he REALLY got serious, he could turn the entire PLANET against the jedi by screwing with gravity. I think that's a little more than they can really fight back against. 😉