In book one of the Inheritance cycle it is implicitly stated that no magic user would ever use a spell without first breaking into his opponents mind, unless he didn’t care if he also perished. With that in mind, Sith and Jedi both use mental tricks, which means they MUST keep extreme mental discipline in order to be less vulnerable to mind probes, therefor Murtagh would default to using his sword until he could gain access to Vader’s mind, if indeed he could, as Vader is so mentally twisted that his mind very well maybe equivocal to a Shades. So that rules blatant magic use out. Even the twelve words of death wouldn’t really do much against Vader as his suit is stuffed full of the most advanced life support systems you can get, (I mean seriously, look at Greivous from Attack of the Clones).

Sword to Sword: Vader wins this hands down. Lightsaber’s are beams of pure light, inside the containment field generated to give them the “Blade” shape, the temperature would have to be around 10,000 degree’s or so, since lightsaber blades can melt through star ship hulls, and the most advanced metals ever mined, smelted or otherwise created. Vader’s saber would simply sear though Zarroc, thus rendering it useless as a weapon.

Thorn: Thorns fire would hurt Vader, but the he would need to be engulfed in flames for a few seconds, Thorn is still a young dragon technically, even with the advance in his age, thus his fire is not as hot as an Elder dragons would be. With that in mind, Vaders suite would have to be at least somewhat heat-resistant; as it could function as an emergency evac suit. As for the force lifting Thorn; its rediculous to suggest it can’t. “Size matters not” is a point yoda makes with a star ship, a standard T-65 X-Wing starfighter, measuring 16 meters in length packed with missiles, fuel, and more engine than you can shake a stick at, and Yoda lifts it in the air like its a joke. C’mon guys, that thing will easily way several thousand pounds, probably around 5 thousand or so. Further example, Kyp Durron in the extended universe pulls a friggin Frigate sized ship out of a suns gravity well. Thats at least 150-200 thousand pounds of steel.

Thus Vader, assuming he just didn’t blow the damned planet up with a death star, or have it razed to the ground via orbital Star Destroyer bombardment, would have some pretty heavy advantages over Murtagh, but due largely to Murtagh’s hearts, youth, stubbornness and ability to improvise with magic (i.e. use it in ways that do not directly influence Vader) I give Vader only a slight advantage.

Murtagh would have no choice but to assume Vader was a magic user, largely due to the way a lightsaber functions, and would most assuredly assume that once Vader blocked Thorns flame with the force.

Personally, I am a great lover of both series and in the end…. How did Vader and Murtagh meet in a clearing? Did Vader skidoo into the book?