Killed eachother by living in groups . Where the group of lesser Sith can defeat a superior one because they're with more. This is Knights of the Old Republic 1/2 and The Old Republic. But Revan, Malgus and Malek are non-canon according to Disney. I can't even take their non-canonizing serious anymore. They say they're non-canon, but they can't be. So yeah, they're canon. I don't care what they say.
More over. Bane used Revan's Holocron. And because he did, that means that she's part of the whole. Then Bane appears in Clone Wars. If Knights is non-canon, Bane is non-canon. If Bane is non-canon Clone Wars is non-canon. It's an endless loop of falling domino's. If there are some comics that intertwine with the lives of the main characters, then I get it. But all the Old Republic stuff, it doesn't make sense for it not to be canon.