Karness Muur vs Marka Ragnos vs Freedon Nadd

Originally posted by AncientPower
It's now confirmed that Nadd murdered Naga Sadow, meaning a physical attack. Therefore we can say for a fact that Freedon Nadd was far more powerful than Naga Sadow, before a century of power growth.

Quote?

And just as Nadd killed his lord Sadow, Kun destroyed Nadd’s spirit here on Yavin 4. These notable deaths likely served to further imbue the moon’s temples with dark power, further fueling the barbaric Massassi–as well as the succession of Dark Lords who would later reside here.
- The Old Republic: Codex Entry: The Dark Legacy of Yavin 4: Part 3

"Eventually, the apprentice became far more powerful than the teacher..."
- The Official Star Wars Fact File

"As Nadd's power grew over more than 100 years of rule..."
- The Complete Star Wars Encyclopedia

From the wording, it seems like Nadd only destroyed Sadow's spirit.

It specifically differentiates between killing and destroying. You can't kill what's already dead.

Plus Sadows spirit makes an appearance in TORs archives.