In the case of Machado's Eva Muñoz, a Jacobson-Moore partner and Senior's vindictive ex-wife, her aggressiveness adds a jolt of energy to this show. Eva has the ability to throw Olympia and Matty off their games. She's their ally, sure, in that she too wants to ruin Senior. But Olympia and Matty can't trust that Eva has their best interests at heart... or even in mind, at all.
The next season of Monster, following season three's Psycho inspiration Ed Gein, takes on Lizzie Borden, the woman who was infamously tried and acquitted for the 1892 murder of her father and stepmother. It's not the first time Murphy has engaged with Borden: Grace Bertrand, played by Lizzie Brocheré, shared Borden's backstory on American Horror Story: Asylum back in 2012, though that series was set in 1964.