Once a mentor to Prince Arthas, Muradin was unable to prevent him from becoming the Lich King. After recovering from a mild case of amnesia, he is now the leader of the Bronzebeard clan since the "diamond-ization" of his brother, King Magni.
While a lot of mages swear by their Fireball spell, Jaina knows that ice can be every bit as deadly as fire. She skillfully hurls Frostbolts at her opponents, chilling them and dealing damage from afar.
To a skilled spellcaster, the laws of thermodynamics are mere guidelines. Using the magical energies to bend the universe to her will, Jaina unleashes a two-wave area attack that deals damage and chills any enemy caught in the ice storm.
Jaina can take care of herself, but it never hurts to have someone (or something) defend you in a fight. The Archmage can sic her icy construct on unsuspecting foes, using its chilling attacks to enhance the effectiveness of her own abilities.