Numina is one of the signature heroes in the City of Heroes universe, although she has not gotten as much attention as the rest of her teammates.
Numina is a skilled sorceress, a skill she inherited from her parents. She has not gotten much face time in the comic, mostly to appear only when the Phalanx needs something they can't do without magic. In one such case she was able to send Manticore's spirit after Statesman's when Statesman was dying. When heroes aren't quite so dead, however, she can heal them on her own.
Early in her super-powered career, Tammy joined the Midnight Squad. In the 1960s, she and her team were sent into a series of caverns surrounding the Earth's molten core. It was there that the Red Threat, a Soviet villain, intended to destroy the world. To save the Earth, Tammy possessed the body of the Red Threat. She minimized the damage, but her body was destroyed. Her consciousness survived, trapped within the Red Threat until he was killed in prison during the Rikti Invasion. Tammy's astral form was at last free. She renamed herself Numina and threw herself into the war against the Rikti. In the war's aftermath, Numina uses her abilities to nurture the next generation of heroes.
She has taken on Infernal as a sidekick, and helps him balance his demonic nature.
Numina stands guard in William's Square in Founder's Falls. Her task force has a limited range of levels 35-37, and leads into Woodsman's trial in Eden. It is rather disjointed and is considered unpopular due to the amount of running around it involves. In fact, almost every villain group that was in at CoH's launch appears in the task force.