When you are Gandalf, you have to save your party from the fire monster when you get past Moria. When you begin the fight, you should equip the spell Staff Strike to Gandalf. When you are going to him, he will shoot fireballs at you. To get to him, dodge the fireballs. If you get too close, he will blow fire at you. If you get as close as you can, he will try hitting you with his unblockable fire sword. Also, it is impossible for you to fall down the abyss. Get close until he keeps shooting fireballs at you and use Staff Strike. After you use the spell, he will be stunned. At this point, start hitting him with your sword only for a few seconds. Then, run back to your team. Keep repeating this to kill it.