Nur in Heroes 5

Hero is able to restore mana in combat gradually by himself. Restoration speed depends on hero level.

Nur is one of those beings that not only wields magic, but is inherently magical. A Djinn master of meditation and mental focus, Nur's battles with Chaos magic across many worlds has led her to develop exceptional magic affinity. As a result of her study, practice, and preparation, Nur is capable of constantly replenishing her own mana.