Instructions
Stand your ground as the Bane Dragon rushes at you, attacking as it approaches. If your character is powerful enough, you should be able to do a serious amount of damage before it overruns and hurts you. Lower-level characters won't be able to do significant damage in this way, but you should try it to see if it suits your style.
Get around behind the Bane Dragon and attack its tail and back. Take advantage of its rapid charges by jumping out of the way before it runs over you, then swing around to attack it from behind.
Prepare for the second phase of the battle when the damaged Bane Dragon turns purple and begins leaping. Continue to stay behind the dragon whenever possible, avoid its projectiles, jumps and charges, and attack it constantly. If you continue engaging the dragon shortly after it turns purple and begins leaping, it collapses and dies.