It is a Sith Legend. Like with the prophecy, it could be a total sham. Plageuis would have to be very powerful in the Force to be able to do what he did.
And Sidious doesn't take chances often, gentlemen. As with Malak and Revan, Vader and Sidious. The apprentices strike when their master isn't looking, so to speak.
Originally posted by General Zodiac
terms of force Plagieus. He could stop people from dieing and Sidious had to kill him when he was asleep. Lightsaber combat don't know.
agreed, though We can take a guess at Plagueis sword skill. If he was that strong with the force, he could prove to be a deadly adversary, though he was more a library guy. Even though, sidious (as he says) choose to kill him in is sleep.
Um, since the technique of immortality was actually the technique of using Sith Magic to enter a younger clone body, and since Plagueis was stupid enough to tell Palpatine that so that Palpatine killed Plagueis in his sleep, no longer needing his master after Plagueis's little blunder, it would have to be Sidious.