Instructions
Keep your distance as a Burning Templar approaches you. They move about as fast as normal Templars, but they are quite a bit stronger. As you approach walls of fire in the Burning Tower, Burning Templars may burst from the flames, so keep a watchful eye as you move through the tower.
Use ranged spells like Crushing Prison or Winter's Grasp. Crushing Prison completely immobilizes an enemy while causing spirit-type damage to them. Winter's Grasp slows enemies down and causes ice-type damage, which is particularly effective against the Burning Templars. If going up against two Burning Templars, use Crushing Prison on one and Winter's Grasp on the other.
Use melee attacks on the Burning Templars after you cast these two spells. If you have mana to spare, use other ice-based spells -- Burning Templars are weak against ice magic. If you are fighting two of them, attack the one affected by Winter's Grasp first. If necessary, recast your spells if they wear off while you are attacking. Keep attacking until the Burning Templars are dead.