The Countess (aka Elizabeth Johnson), played by Lady Gaga, is a 112-year-old ex-aspiring actress and now a vampire who owns the Cortez Hotel. She is glamorous, aloof, and goes through a series of tall brunette male lovers including fellow bi, Will Drake.
In addition to the romantic arc of Donovan and the Countess, there are many other connections of varying intensities happening. The Countess finds another partner in the drug-addict model-turned-vampire, Tristan, and promptly kicks love-stricken Donovan to the curb. Later in the season, we discover that the Countess has been in relationships with women as well, including Ramona Royale. In her backstory, we learn that she was in a throuple with Rudolph Valentino and his wife Natacha Rambova.
After Valentino disappears/is locked in a hidden room by her future husband, she spends the next few decades in relationships with various men who look a lot like him.
She is in charge of the Hotel and its inhabitants living and not, feeding off unsuspecting visitors.