Alcyoneus, a radio galaxy 3 billion light years away, now ranks as the biggest galaxy ever discovered - and it stretches for FIVE MEGAPARSECS (16.3 million light years). A single galaxy that's 5 megaparsecs in diameter??? That's as far as it is from the Milky Way to the Asterion Dominion! So that's, you know...big.

I wonder if it's the Rasu's home galaxy? Just speculating.

“The Biggest Galaxy Ever Found Has Just Been Discovered, And It Will Break Your Brain”: https://www.sciencealert.com/at-over-16-million-light-years-across-this-is-the-biggest-galaxy-ever-discovered