I think Palpi would attack Exar with lighnings (if you've read Dark Empire, watched the movies and all sources about him you know that he only mastered that) or with lightsaber. Vader would attack Exar with lightsaber and try to overwhelm him with his brutal power, or choke him. Exar would be amused for a moment with those two clowns and then used one of his spells to send them to some other dimension or to blow their veins or create immediately some nasty creatures (we know that he developed hundreds of predatory species on Yavin) that would just eat them. In any case he would be unbeatable, especially if you notice the fact that
to destroy Vader & Palpi it took a few force-users while to destroy Exar it took thousands.
Vader and Palpi are present in dozens of comics, novels and shortstories. In all of them Palpi always uses lightning and Vader is same as in the movies - brutal thug with lightsaber who overwhelms opponents with raw power. Not impressing.
Agreed - I only gave movie example to show Jaden how stupid is criticizing EU source only becouse we don't agree with it.