Yrbeth in Heroes 5

Dark Ritual ability is more powerful, enabling the hero to regenerate mana even beyond the normal max mana cap. Amount regenerated over the cap depends on hero level.

Yrbeth was a child gifted with powers of focus and concentration beyond her years. Training in the eldritch arts like many of her kin, Yrbeth's ability to focus her powers - famously displayed during an earthquake - permits her to accumulate more magical energies than is normally possible. The night before an important battle Yrbeth often goes sleepless, spending hours in meditation to prepare herself.