Obi-Wan proved that he was better than Darth Vader in The Revenge of the Sith when he defeats Vader when Vader was at his height in power. And the only reason Vader killed him in A New Hope was because Obi-Wan sacrificed himself to help the others escape.
Darth Vader's old master was Obi Wan.
Yes, Obi-wan and Darth Vader fight twice. Once on Mustafar, where Obi-wan was the victor, and once on the Death Star where Darth Vader killed Obi-wan.
Darth Vader's Master is technically the Emperor when he was a Sith, but when he was training as a Jedi his master was Obi-Wan Kenobi
No, he does not. Darth Vader's first apprentice (Galen Marek/Starkiller) is killed by Emperor Palpatine/Darth Sidious.
Obi-Wan states to Darth Vader, "If you strike me down, I shall become more powerful than you can possibly imagine."
Obi Wan
darth vader
possibley Darth maul because he wasnt trained as long alough is a lot quicker.Darth Vader is very strong with the force he can throw objects with both hands on the lightsaber. and anakin put up a better fight vs obi wan.it realy depends on the area wich they were to battle.
Obi-Wan had already known that Anakin had 'turned to the dark side' and had become the Dark Lord Darth Vader. (he realized this shortly after he did [see episode III])
yes
Obi-Wan cut them off in the fight on Mustafar
They're almost polar opposites. The only thing I can think of is devotion to their cause. Darth Vader fought valliently for the Empire and the Sith, Obi-Wan Kenobi for the Republic (later the Rebellion) and the Jedi.