Malak's power was being amplified by the dark side of an entire race and it's technology. Not to mention that he was described as "unstoppable" with the power of the Star Forge.
Canonically, Malak only has one confirmed extra life. For all we know, Revan drained the remaining Jedi from their slumber! And where was it said SPECIFICALLY that Malak's powers were substantially increased on the Star Forge?
The fact that he could control such as device without being killed, is a testament to how much he learned at Malachor, as well as his own power. Now Kun has never even been to Malachor.
Malachor is full of useful tidbits of Sith lore, that's true. But Kun had access to Sadow's and Nadd's stash of information. We don't know how great the knowledge on Malachor was anyways. Controlling the Star Forge only makes him more powerful than Council Members, who are potentially as weak as Coleman Trebor. Still leagues below DE Sidious.
Darth Traya, a powerful Sith learned a technique that could instantly kill three skilled Jedi masters. A technique from which there is "no defence."
No defence? Unproven statement. It kills three powerful masters, but ROTS Sidious did that too, with his saber, in seconds. Now, does that mean he can saberape everyone? No. We've only seen the instakill being used once. This is like saying Vader's force choke has no defence, because no Admiral ever resisted it.
Now Revan, who was there first, possesses much more raw force strength, intelligence, and overall more talent and thus certainly learnt more from the teachings at Malachor than even Traya. Indeed, it is because of Revan that all the other Jedi in KOTOR fell.
Now, where are you getting this from? More raw force strength? Intelligence? Overall talent? When has Revan ever demonstrated being far stronger than Traya? Never. It was not because of Revan that the Jedi in KOTOR fell, it was due to a number of things:
(40 years prior)
The Freedon Nadd uprising, the Sith War
The Mandalorian Wars
The Second Sith War (Revan)
Sion's Assasination group
A couple more things I might be forgetting.
He has never accomplished anything near the greatness of Sids (having all Jedi destroyed and conning the galaxy).
His command of the force is incredible to say the least. The Rakatan's in game describe his force storm as lightning raining from the sky, slaughtering their scouting parties.
Those force storms are small sparks compared to Sidious' power. Frying a few primitives is not impressive at all. And if he had the power to create uber Force Storms, he would have created them.
The very fact that he was described as "Power" by Kreia, who had lived during the times of Exar Kun and Ulic Qel Droma, speaks volumes for him. Finally, in KOTOR Revan is described as the only Jedi that can stand against the Ancient Sith, enemies who are akin to Naga Sadow and Ludo Kressh.
Oh gee, biased old Kreia. Notice how she was the only one to describe him like this, even though there were others who were closer to him and knew him more after the mindwipe. The Ancient Sith are a bunch of wimps now for all we know (like the Rakata). After the Hyperspace War alot of stuff was lost. We have no clue how powerful they are now.
Now, Revan has a chance in a saber fight. But since we haven't seen him fight with a saber I can't judge. Revan is toast in a force fight.