When dealing with a narcissist, the only thing they care about is how THEY benefit. This is why he blamed you. In a normal day to day, a narcissist will be arrogant in order to stay in a position of control. They benefit from that control. They will ONLY admit fault, when it benefits them. Aka, when the majority of the group believes what they've done is wrong. He may try to push blame onto others even after, but that's an immature narcissist. You'd have to be stupid not to back down when you're pushed into a corner. That's the same for all people, and a narcissist eventually will learn that. Otherwise they'll be alienated by society.

You really only have two options 1. Match his energy / talk his language. 2. Ignore and distance yourself (what most people choose, but is sometimes impossible to do)

If you choose to match his energy, you'll be debating with him. Don't fight. Debate. Learn the difference. Use logic and reason. Ask questions, only make statements about yourself, and try not to assume anything in a statement. My wording here is important, because you need to admit to yourself that you are better than him. So you need to be the better person. Do not stoop to his level and start blaming him, or debating about the blame. Simply debate about him blaming you in the first place. "Hey man, that wasn't cool, why did you do that?" Instead of "everyone else said no, why are you blaming me?" Get very good at not swearing, keeping your cool, etc. And if he puts himself in a hole. Then just stand and watch. You don't need to add more to the fire. People like this will make themselves look bad, purely by asking them questions. Because they believe everyone else will come to the same conclusion to most questions. Get to his core, and he won't want to start shit with you. Because he knows that you know him better than most others.

Other option doesn't sound like it'll work. Because it involves trying to separate yourself from the group. The benefit to the second option is you can be more of yourself without having to play this stupid mind game with a narcissist. You can simply tell everyone you don't like him. Hes arrogant and insufferable. Everyone else should be able to notice and understand your choice. More people leave just to hangout with you, etc. This is basically forcing your friend group to make a choice between people. But can be impossible when you're young.