Yujen

"'I am the great Wizard Yujen. Surrender now or I'll have no choice but to kill everyone.'" Yujen is one of the wizards the reside within the tower. He is a talented wizard probably.

So far he's killed the Void Walkers by pulling the airs from their lungs, it's not fully known the level or limit of his abilities. He is known to wear a set of bright red robes.