When speaking over these domain names with a classmate we agreed that SkiesOverSanctum would be the best option. It's punchy, catchy, and unique. SOS, while shorter, is also a distress signal, and AecoLegends is derivative.
I like SkiesOverSanctum best as it best displays what my website is about without being too convoluted. Since the game is about exploring a series of floating islands, SkiesOverSanctum best creates that feeling, and the alliteration gives it a pleasing rhythm.