Monarch of Temra, the nation which shares the expanse of an island with Kells. Maeve enacted a plan to overthrow King Conchobar and take his throne. After discovering her armies weren't strong enough to defeat Kells alone, she sought help from the dark fairy, Mider. He, in turn, gave her the Ram Staff, and a powerful, green Rune Stone. With this powerful new gem, Maeve could summon creatures from the deepest pits of Tir Na Nóg and send them to wreak havoc upon Kells. In return, Mider asked for her help in taking over the land of Tir Na Nóg itself. While she is willing to work with Mider, Maeve only trusts general Torc implicitly.
She was later revealed as the mother of the young Mystic Knight Rohan and of her servant Lugad. During her final campaign against Conchobar, Maeve takes over Kells until Lugad frees the captive Knights during Maeve's fight with Rohan. Maeve used her full magic to assume the form of a Nāga-like creature with eye beams. It was only the combined magic from both her sons, that could defeat her and revert her to human form. This also caused Maeve's rune stone on her staff, the source of her personal sorcery powers, to be overpowered and disappear. Maeve was then rendered powerless, and was banished to another island by Conchobar.
As she saw her son for the last time, Rohan himself asked if she had anything to say to him before her banishment. She then replied that he'd been trained well and that he was a great warrior except that he'd just fought on the wrong side, so he asked her to be taken away.
Maeve is a ruthless, power hungry, and cold-hearted tyrant while also intelligent and manipulative, being able to convincing and deceiving people to do whatever she wants. She also made it clear that she won't establish a peaceful relationships with Kells, establishing made a pact with the dark fairy Mider for greater magic power regardless of its costs, and intolerant to her subordinates' failures, which shows to what extent she's willing to conquer the entire island. In fact, she's more than eager to hunt down and destroy those who stood in her way for power, even those who have familial relationships with her. It's also suggested that Maeve was the one who instigated the conflict between Temra and Kells by attacking the latter kingdom in an unprovoked attack given to her ruthlessness.
Maeve had no true attachment to her sons, having abandoned Rohan when he was little which led to him adopted by Cathbad and left Lugad under Nemain's care. In fact, she only sees the latter as a disposable brute and made it clear that she would banish him to the same prison she incarcerated Nemain once he outlived his usefulness (much to the dismay of Lugad that he turned on her out of broken heart and persuasion of Deirde) and her opinion about Rohan remained unchanged even after figuring out he was the very child he cast aside. The tension between the mother and two half-brothers was so great that it led to the latter two join forces to defeat her and disheartened Rohan had Maeve banished for her crimes.
As the greatest adversary of Mystic Knights, Maeve is highly versed in both arts of physical and magical combat. A testament of her magical abilities best displayed through her ability to summon and command all kinds of monsters to help her cause, can vanish in a blur of light and transport herself instantly over large distances, and even assuming Nāga-like form that can project energy beam from her eyes. While possessing great power over magic, she also a highly-skilled fighter, being able to defeat the greatest of warriors in single combat. Using only a sword, Maeve was able to defeat both Garrett and Rohan while wearing their full armor and using their powers. During fights, she uses her sword fighting skills as well as kicks, throws and incredible agility and acrobatic moves to defeat her foes.
Maeve is a powerful leader and master tactician, able to anticipate on her enemies and develop tactics and schemes to outwit them and achieve her goals. She also remarkable when it comes to both convincing and deceiving people.