First of, I don't think "Sidius" is the most powerful sith. I'd put Bane up there when he was in his prime before he fought Zannah the last time. Also considering Bane and his "rule of two", Sidious did not prove stronger then his last master. Broke the fundamental rule that made the "rule of two" superior over all others, by poisoning his master and not facing him.

 

Second, if you read the novels Luke during his prime would destroy Sidius. Back during the movies or even lets say before the new jedi order novels. Luke would loose hands down. Its not much of a topic realy Luke is a BA in the novels.

 

But in my opinion where the novels stand now, Luke in his prime is the single most powerful force user, outside beings like Zonama Sekot, "the ones" featured in the clone wars series and legacy era, and perhaps the "celestials" in fact anything around 30,000 BBY ish doesn't count when I put Luke as the strongest. He may have not learned all the fancy tricks that were lost after so many Jedi vs Sith wars. But looking at all he accomplished hes pretty powerful.

Except Sidious was the most powerful sith lord ever, and he did surpass his master. He learned everything from him, then killed him. Where does it state in the RoT, that an apprentice must face his master in open combat? All it says here is that.

"This transfer of power would only take place when the Apprentice takes their Master's life and finds a worthy student to repeat the cycle."

There is no specific line where, there needs to be a certain way of killing the master only that he must be eliminated.

but he did not learn everything he even admits it, in Episode 3.

He knew he could not defeat his master Darh Plagueis face to face, so sidious killed him in his sleep...Sidious admits his master was more powerful. One of the big ideas Bane came up with, was each apprentice would defeat his master in combat, so each Master would be stronger then the last. Also to name a few sith lords to contend for the title (not all)

(Darth Bane does mention it, its mentioned a few times through out the Darth Bane trilogy, even looses faith in Zannah at one point when she uses assassins)

Exar Kun

Darth Bane (arguably zannah cause she kills Bane but then again Bane was not in his Prime and was already dying)

Revan

Darth Andeddu

id put them all above Sidious, also were slightly of the topic so sorry

but he did not learn everything he even admits it, in Episode 3.

 

He knew he could not defeat his master Darh Plagueis face to face, so sidious killed him in his sleep...Sidious admits his master was more powerful. Also to name a few sith lords to contend for the title (not all)

 

(Darth Bane does mention it, its mentioned a few times through out the Darth Bane trilogy, even looses faith in Zannah at one point when she uses assassins)

 

Exar Kun

Darth Bane (arguably zannah cause she kills Bane but then again Bane was not in his Prime and was already dying)

Revan

Darth Andeddu

 

id put them all above Sidious, also were slightly of the topic so sorry

Sidious is the most powerful sith to ever live. He could make wormholes that can destroy surfaces of planets and entire fleets. He is very powerful though I think he reaches this power in the novels.

That was all during Dark Empire ( i read the comics not sure if its in Novel form)

Those powers Sidious had were also his downfall so that doesn't say much

During the golden age of the sith and the great sith war eventually following there was plenty of sith sorcery and super powers / technology going around. One of the ways Ossus fell. Palpatine may have wielded unique powers. But he was not the first to weild such immense power.

It took thousands of Jedi all at once to Destroy Exar Kun (to include Jedi Masters)

It took a couple to defeat sidious (this is also before Luke was in his prime and Leia barely trained in the force, considering this Luke would become much stronger then he ever was when he faced Sidious)

Bane slayed any jedi who faced him, fell to a sith