The opening played here, is just exceptional, he never plays that, he always plays the bishop opening and as he is older than me he taught me that the bishop opening is the best.
Is my friend [removed] a cheater?
He cheated with the best players at my school online or he wouldn't be able to beat them.
They even have the proof that he cheated.
Accusations of cheating aren't allowed in the public forums. If you think someone is cheating, press more on their profile and then press the report button:

Not to be rude or anything, but I don’t think you’re allowed to do that to another member without them knowing
You're not allowed to publicly accuse someone of cheating. Just delete the name and edit the topic as "Is my friend a cheater". Chess.com's policy on this is quite strict...
Few days ago, my school friend gave me a friend request to play chess online. Although I have beaten him a lot of times in practical (offline) chess, this time while he was playing with me online in rapids, he defeated me like nothing, I was literary shocked, because he is 400 rated whereas I am 1009 rated. After the game review I saw he had an 96.9% accuracy. Is he cheating using stockfish? And how to ban him from chess,com.