As a devil's advocate, I'm often "Them" in your conversation, so I'll try to answer based on what would influence me, and leave it up to you to determine whether it's a general solution.
The trick to dealing with them is that their position typically involves expending a great deal of energy rapidly. If I want to challenge your claim that the Hyperloop is awesome, the first thing I need to do is to come at you with enough force to keep you off balance. Otherwise, we run the risk of the conversation becoming grey instead of black and white -- which is bad for such an attacking personality.
The most fundamental thing to understand about this approach is that it's all about making you lose, rather than trying to make them win. They're not trying to "win" the argument directly. They're trying to make you "lose" first, and then proclaim themselves the winner by default. That's the game. However, if you refuse to lose, or refuse to lose meaningfully, then they can never claim their win by default.
So the first trick you can leverage is to simply only engage with this person in simple boring single-round sparring on topics that you don't actually care about. Did you actually care about the Hyperloop? Then don't ask them. This solution is exemplified in several answers, including NVZ's.
The next trick is the one mentioned by Andrea. If you don't make any statements that can be construed as an opinion, they can't attack it. This may be boring, but it can be entertaining to some people. From time to time, when my Devil's Advocate hat is hung up, I'll have fun trying to refuse to be goaded into verbalizing an opinion. It's actually a pretty neat game, I think. The key here is that they can never make you lose, so eventually, they will become frustrated because it's the only way for them to win.
Beyond that, the question I'd ask is "why do you want to have this acquaintance in the first place?" What value do you get out of it? If they're only annoying, just stop hanging out with them. If there's a reason to hang out with them, reflect on that reason. Maybe you just have to work with them as a coworker. Use this to your benefit. Have a meeting you want derailed? Invite them, sit back, and watch the fireworks! Maybe you're feeling lethargic, with no energy to get up and fight. Go hang out with them. Let them put all the energy into the fight, leaving you with more than you started with.
There are more advanced approaches too. If you can keep a conversation moving, it's hard for them to lay into any one topic. By the time they plan their attack, you've moved on. I, myself, have trouble with this approach, but I've seen it used very successfully. Eventually, they lose track of what They should attack.
Having a discussion with them can actually improve your conversation skills greatly, though no credit can really be given to them. If you can avoid being skewered by them, then you're that much more invulnerable in a discussion where your partner isn't trying to make you lose. If only They understood this more, and held their punches in a way that made it easier to learn.
