Can Master Chief kill Darth Vader?

Answer 1

There are factors to point towards either being a victor.

For example, Harry has extensive magic to use including expelliarmus, which may remove the saber from DV's hand, as would wingardium leviosa. He can also protect himself with protego, or launch attacks like any unforgivable curse, petrificus totalus, and other small hexes.

On the other hand, DV has extensive use of the force which he can also use to perform certain actions, like picking up objects and making them fly at Harry. However, he cannot protect himself as well as Harry can, and Harry can protect himself from the attacks that DV makes on him.

All over, whilst both stand a good chance, it is most likely that Harry could kill him as he has a simple spell to do so whilst DV must do so by not only physically hurting Harry, but also without getting killed himself and getting around Harry's protection to attack him at all.

Answer 2

The over-exuberance of respective fans notwithstanding, the first thing to say is "No" on logistical grounds.

You see, Master Chief was said to have been born in the 26th century in our galaxy, while Darth Vader was born "a long time ago" and in a galaxy "far, far away". So Annakin was dead and gone long before John was born.

On a taking them out of their respective time and places and throwing them together, one would think the smart money would be on Darth Vader.

This is based soley upon "the Force", a semi-mystical power that allows for telekinesis. No amount of technologically enhanced cyborg powers will do much good when Darth can just squeeze your heart to a pulp with "the Force".

(Though admittedly, that was an aspect of "the Force" that no one ever seemed to use in the Star Wars universe.)