The Hardcore guild <HC Elite> has defeated C’thun on Classic Era NA realm Bloodsail Buccaneers. This is the same guild that toppled Ragnaros during the Road to Rag event in early 2022, as well as Nefarion only a month ago! Warcraft Logs for the Kill.
What makes these Hardcore Kills on bosses so special is that each character in the raid is one-life, meaning they leveled from 1 to 60, got gear, and raided dungeons and other raids without ever dying.