Challenge Idea: Let's do this "the old way."

I was watching a flick on TV and the two armies were about to go to battle. The wise sage of a leader (the star, of course) tells the bad-guy's general: "let's resolve this the old way. Your best against my best and we leave our fates in their hands." (think: Achilles/Boagrius - that's not what I was watching, but it's the same old thing).

Why don't we do that with survivor? We get one team with 3 people and one with 5. Instead of leaving 2 on the bench - let's decide it "the old way." The smaller team chooses a challenge: stamina, strength or smarts and they choose their champion. The other tribe chooses their champion and the winner gets immunity and the loser? Goes home. That's right. Don't tell them beforehand that the stakes are this high - let it surprise them! Or, not.

Okay, you don't HAVE to whack the loser, but that would be hilarious. But, we could award the cool little immunity idol based on the winner of a champion v champion battle. Your thoughts?

Also, I'm curious: what kinds of challenges can you think of? Evvie knowing the challenge last week was lame. Time for new stuff.