"Moon Lord is Cthulhu's brother" - Cenx; I'd say he is "Cthulhu's brother from another mother", because Lovecraft have not mentioned about Cthulhu's "brother" in his stories.
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Crowno
You guys take this so serious, lol. Has anyone thought about the hypothesis that she might be joking? haha
Crowno
But let me tell you my opinion: He is what you guys want him to be. If we didn't gave him a proper name, it's meant to be ambiguous. I also think that if you believe he is Cthulhu, you shouldn't see him as the Lovecraft's Cthulhu, but rather our own version inspired by his work. TLDR: I'm not saying it's Cthulhu, but I'm not saying it's not him either ;p
Crowno
For all effects, he is Moon Lord, nothing more and nothing less. What you make of Moon Lord is up to you 