Crisis Core: Final Fantasy VII/Superboss - Minerva

The superboss of this Final Fantasy is Minerva, a powerful goddess found at the end of the ../M9: Great Cavern of Wonders/ mission set.

How to unlock
In Chapter 4, you will receive a mail from the Treasure Princess, it will unlock the mission M8-4-1, you will need to beat every mission from M8-4-1 to M8-5-6 to unlock ../M9: Great Cavern of Wonders/, then beat every mission from M9-1-1 to M9-6-5 to unlock M9-6-6: The Reigning Deity.

The fight
Minerva has 10,000,000 HP in Normal, 77,777,777 HP in Hard. She has several attacks which can instant kill you. Her Limit Break deals a flat 75,000 damage to your HP and removes every buff you have. Because of this, there are several requirements to be able to defeat her:
 * Have more than 75,000 HP (having at least one HP UP++ (M) HP+999% materia or something similar is mandatory
 * Have the Mug materia (Minerva holds 99 Phoenix Down, steal them from her at the beginning of the fight)
 * Have the materia Costly Punch (this Materia is an attack that ignores all defenses from the target and does flat damage at the cost of your HP)
 * Have VIT & SPR to the highest value possible (the max is 255)
 * An accessory such as Brutal (found as a reward for beating M-7-4-6 or Genji Glove (found in a treasure chest of M9-6-4) in order to up your damage limit from 9999 to 99999)
 * An accessory such as Adaman Bracelet (it can be stolen from Grandpanzer, as a finish reward in M-7-3-6, found in a chest in Mission M9-2-4 and M9-5-4) or Genji Armor (obtained by completing the DMW to 100%)

Reward
You will get the Divine Slayer accessory.