Victors write history. Had I taken the Stone of Tear, history would have shown I was born on the slopes of Dragonmount, of a woman never touched by a man, and that the heavens opened up in radiance to herald my coming. The sort of thing they say about you, now.
— Mazrim Taim to Rand[1]
The highest military rank of the Asha'man, the M'Hael holds the supreme rank of Leader, second only to the Dragon Reborn in the Asha'man organization. M'Hael means "leader" in the Old Tongue.
The only M'Hael was Mazrim Taim, who created the position and title himself, acting on his own outside of Rand's command. M'Hael is also the name given to Mazrim Taim as one of the Forsaken.
With the open revelation of Mazrim Taim as a Darkfriend and Forsaken, as well as his defeat during the Last Battle, the future of the title and Black Tower leadership is unclear, especially with the believed death of the Dragon Reborn. Logain commanded the Asha'man loyal to the Light during the Last Battle and, like Taim, is a former False Dragon who began channeling long before the Black Tower was founded. Therefore, it is probable that Logain will lead the Asha'man following the conclusion of the Last Battle. However, whether he will use the title of M'Hael - or even whether he will lead the Black Tower as a sole leader - is uncertain.