Actually there is not much proof that Kun is a much better duellist than Vodo IMO in saber combat and no real proof that his staff is more/equally powerful to his saber because....
You were saying?
Vodo's stick can be broken.
Funny how it didn't break before Kun got serious. Thwapping things with a lightsaber tends to break them.
Vodo hit Kun with his staff, and as most it broke his arm.
He hit him, while Kun was still his apprentice in a completely different fight. And it broke his arm? What are you smoking?
We know that before Kun went to the darkside they sparred. At the end of the sparring Kun took two swords and broke Vodo's staff. At that moment he told Kun that he was the best student he had ever trained.
Yes. And we know that Vodo beat him before Kun called the second saber to his hand. What's your point?
After a while Kun turned to the dark side and confronted Vodo, who defeated him if I remember it right. (Broke his arm or something)
You remember incorrectly and you're making things up. Kun's arm was never broken, he only fought Vodo twice. Once as an apprentice, the second time as the Dark Lord of the Sith where he toyed with and curbstomped Vodo.
Then a time after that Kun confronted him again and Kun broke his staff to win. So actually, Kun could be equally good as a saber user as before, he broke his staff then too, but he sure as hell wasen't the better duellist.
Oh, he wasn't the better duelist? That's why he literally toyed with Vodo the entire time and then, the minute he got serious about fighting, Vodo found himself cleaved in half?
QED.