Proof of stake staking with Ethereum, Cosmos, Polkadot, Tezos, Solana, Kava, etc
Calling it "Etherium" to mock blockchain advocates is extremely immature and not appropriate for Hackernews, no matter how deserving of ridicule blockchain advocates are.
It's just a spelling mistake.
Nope, this individual has been commenting for years on Ethereum stories, and been corrected multiple times.