Featuring the following heroine!

Roma

AKA: As the Protector of the Multi-Verse, Roma is known as the Omniversal Guardian. 
She's also called the Goddess of the Northern Skies.

First appearance: Captain Britain 1

Team affiliation: The daughter of Merlyn, Roma made herself known to Brian Braddock after he died, offering him another chance at life if he became protector of Great Britain. She often appeared to him, offering guidance, encouragement, or chastisement. Roma needed the help of the X-Men to free herself from her cosmic opposite, the Adversary; in gratitude, she resurrected them when they sacrificed themselves to save the planet. After her father went AWOL, Roma took over the Starlight Citadel on Otherworld and assumed control of the Captain Britain Corps. When it became clear that her own manipulations of Excalibur were in turn being manipulated by her father, Roma asked for Meggan and Brian's help in destroying the nexus that Merlyn used for power on Earth. This resulted in the destruction of Excalibur's headquarters as well, requiring the super-group to relocate to Muir Island. Haven's messing about with powers beyond her ken allowed the Adversary to be reborn; after expending all her energy containing the Adversary, Roma fled to Forge and demanded he return to his role as the mystical Maker.

Favorite quote: "I do only what circumstance demands, Brian Braddock." (Excalibur 47. Roma explains to one very cross champion why she has deliberately restricted his powers.)

Powers: Roma is a sorceress of the first order, and has dominion over all time and space. That being said, she still has issues with her father (whether or not he is "the" Merlin has not been made clear; he keeps changing the way he spells his name, further muddying the waters), can't handle the Adversary without help, and tends not to trust her various champions with the truth.

Favorite storyline: Excalibur 47-50. Roma saves the multiverse and fakes out her cold fish of a father.

Least favorite storyline: In Uncanny X-Men 229 Roma provided the Siege Perilous for the X-Men's use, thereby setting in motion one of the most ridiculous storylines in a franchise ripe with ridiculous storylines.