You must really believe in your "Castles in the Sky" if the website is "One Ill Building.com."
Actually, it turns out that www.oneillbuilding.com isn't even the proper URL, it's www.theoneillbuilding.com.
A scoop at Curbed reveals that a rapper bought one of the penthouses and two apartments below the penthouse to use as His and Hers closets (at 1.4 million a piece). Who's the rapper? Who's the Her? It's Nas and Kellis.