In the final Megalith, you can find six monsters called Lords: Water Lord (Bols), Beast Lord (Towa), Sound Lord (Isis), Stone Lord (Moi), Tree Lord (Mika), and Fire Lord (Sargon). These are actually Edel Litters. If you defeat them, the type you defeat will not appear at the last battle with Egg. For Water Lord and Fire Lord, you will fight them in Party Battle. For the other Lords, fighting is in Duel. There are some specials rules for this battle:

The character in "5 minus number of characters in main party" fights with it. For example, if the number of main party is 3, 5 minus 3is 2. The character in the second position in Sub Party fights.

If you stay alive after 15 turns, you will win the battle.

If you lose, you can still continue and are not counted as "defeated".

The character that fought with Lord will be out of the party.

You cannot battle more than two Lords.

Also, the Fire Lord shows up at Hahn Nova.