Right before the final battle, when your under the draw bridge, you'll see another room. After you go though some fighting trials, you'll come to the ultra tough Skull Lord. He casts a spell called "Timat" that causes enough damage to kill instantly. Heres a tip. If you have lots of men around you, the damage is less because the timat has to hit them, too. If you beat him, you'll get the Justice Sword and the Timat Staff, which lets you cast the "Timat" spell.