From Wikipedia:
Iwan Rheon as Simon Bellamy initially turns invisible when ignored, and later at will. In Series 3, he displays the power of personal precognition; he can see the outcome of his actions before he actually tries to perform them, and can therefore choose to perform the act or not.
Lauren Socha as Kelly Bailey can hear people's thoughts (telepathy and empathy), usually when somebody judges her, but later demonstrates control. In series 3 she has gained the intellect of a rocket scientist, with the limitation that the level of her knowledge is limited to rocket science and propulsion systems.
Nathan Stewart-Jarrett as Curtis Donovan can rewind time to undo undesirable outcomes when he experiences regret or remorse. In series 3, he can change his sex at will.[citation needed]
Antonia Thomas as Alisha Bailey causes overwhelming sexual arousal in people with whom she makes skin-to-skin contact. In Series 3, she gains a form of clairvoyance, being able to see through the eyes of others to observe where they are and what they are doing.
Robert Sheehan as Nathan Young (series 1 and 2) is immortal and can interact with the recently deceased. He later acquires the ability to warp reality.
Joseph Gilgun as Rudy Wade (series 3) splits into two identical duplicates at moments of self doubt, with polarised self-confidence, one demonstrating arrogance, the other having more empathy.