Right now it's Mirage. But it's a toss up between him, Crypto, Caustic, and Lifeline. Low-key Caustic can carry a team if everyone stays near him. And Mirage can almost Solo a squad if he can keep fooling them with his clones. Crypto is invaluable and criminally underrated. And Lifeline is just plain awesome, especially after her new rework. Who's your favorite?