My friends' and I accounts were hacked.

Yesterday I woke up to some odd messages from my friend, talking shit to me. He was typing unusually too, with near perfect grammar and capitilisation, which my friend usually doesnt bother with. I thought nothing of it until a few hours later, my friend told me he hadn't played on this account all day.

Let's call my friend who just got hacked A, my second friend who's in game with the hacker C, and me Y.

C has been playing games with the hacker, not knowing that it wasn't A he was playing with. When we told him, he shared screens with us on Discord to let us see what was going on in the game. Indeed, the hacker was playing champions that my friend usually plays, namely Vayne and Kog'Maw, but he was typing weirdly. Near to the end of the game, the hacker told C, "I am going to hack your account."

And as soon as the game ended, C got the notification that his account had been logged into from a new location, and it freaked us all out hugely. A's account was only level 17 with nothing on it, but C's account was over level 200 with 100+ skins on it. He changed his password but for some reason neither of them sent a ticket despite me begging them to.

Now it gets weirder from here. The hacker managed to hack C's second account as well, despite him never mentioning the name of this account in any DMs. It was incredibly strange. C wasn't kicked out of the account, but the chat kept disconnecting, and when it reconnected, there was a new message sent to C's main, and it looked like he had sent it, when we knew he hadn't.

That was weird enough. But then, after adding up the hacked accounts and speaking with the hacker, one of my accounts was hacked into as well. The weirdest part was that it was a completely different account than the one I'd contacted him on, and an account I almost never use. I don't realy care about losing it - I suspect he hacked it because it's my highest level account - but he typed to me, "Thanks for the account."

This has lead me and my friends to speculate that the guy is somehow getting our IP addresses to see our accounts, and hacking into accounts with the same IP. This happened completely out of the blue. A never shared details. This was utterly random and we have no clue how the hacker even knows who we are. We've never posted on social media except for one or two Reddit threads in the past. It's honestly creepy, and I'm unsure of what I should do. Apparantly, C got his account back, but I'm unsure about A.

What do you guys think of the situation? It has me creeped out as fuck.

TL;DR: Me and my friends got hacked despite never sharing our details anywhere. The hacker keeps talking to us via our own accounts and it's got us creeped out.