On the battle of The Dark Lord Sauron, use Morgul Decay just like was done on the Witch King. The Dark Lord knows Berethor is strong. He will probably use Darkest Fear on him, then he will not be able to battle for a while. Use Elven Rage and it will do somewhere from 16,000 to 19,000 damage if it is a critical hit. Do not use Elegost. He misses often when you fight the Dark Lord. Try Eaoden, but his move Drain Health still only does 4,000 HP. Use Hadhod and kept using Cleaving Wound.

Have Hadhod, Elgost, and Berethor in your party. Make sure your Perfect meter is full, and you have Hadhod's passive skill that lets him always get criticals when the Perfect meter is full. On your first turn, use Morgul Decay on Sauron. On Berethor's first turn, have him use either double attack with Company Migh and War Call, or Company Night if you do not have Double Attack. Next, add the item that adds light damage to your melee/ranged attacks to Hadhod. He should now do about 33,000 damage every time he attacks.