Spoiler Alert! Read and watch if you dare . . .
- Ereshkigal, the enemy awaiting you at the end of the Ultimate Lair, is a flying creature, which is of great tactical significance when planning your Schemata setup. When defeated, it relinquishes the Ultimatus garb, a Diamond Matinee Necklace and, perhaps best of all, a +10 increase to your Maximum ATB.
- Our strategy here is recommended if you wish to obtain a perfect five-star rating on a first playthrough. For best results, you should set up your Schemata as shown in the Complete Official Guide. The only required recovery item is one elemental Potion corresponding to the elemental spell in Schema 1, but you may want to bring at least one Ether, one or two items that bestow Bravery, and a revival item just in case things go awry. Note that you can pick up some of these on the floors preceding the Ereshkigal encounter.
- Initially, your opponent will erect two barriers and bestow buffs. After this, its behavior centers on countdown cycles consisting of “Meteor unleashed”, “Words of power intoned…”, “Gathering energy…”, “Invoking Meteor…” and, finally, “Meteor”. The power of Meteor increases with each successive casting, corresponding to multiple additional hits of 3,000 damage that cannot be mitigated by anything other than Guard Defense. Between individual steps of this countdown, Ereshkigal will use its other abilities, the most worrisome of which is Resonance. The good news is that Ereshkigal’s speed is fairly pedestrian and can be further decreased with Slow. This is the key to a successful strategy with a low-level Lightning.
- Once half of the monster’s HP is gone, it will use Awakening and forego any defensive barriers. This relaxes its resistances but doubles its Strength and Magic. In addition, there is a shorter delay between its actions. Most significantly, its ultimate ability Super Nova becomes available – this attack is almost impossible to survive without Defaith, as it ignores resistances in the same way that Meteor does. Fortunately, if you properly execute some variation of our strategy here, you can completely avoid Resonance, Super Nova, or anything beyond Mega Meteor, possibly even the initial Meteor if things go well.
- Start of Battle: By hugging the walls around the room in which Ereshkigal resides, you can acquire an easy preemptive strike to reduce its starting HP by 25%. Always begin the battle by inflicting Slow. Use Attack in Schema 1 to jump into the air, then alternate between Schemata 2 and 3 to cast long chains of elemental spells. Remove the Protect cast by Ereshkigal with Heavy Slash and refresh Slow constantly when you are low on ATB in your other Schemata. Don’t forget about your Quick Stagger 75% auto-ability; soon after the Stagger Wave turns red, you should be able to stagger instantly by using Heavy Slash in Schema 2, most likely in correspondence with Protect Feeder.
- Increasing Stagger Levels: Once you achieve stagger, you need to reach a Level 2 stagger very quickly. The Fog inflicted on the enemy prohibits it from using anything other than Grand Impulse, a physical ground attack that has no effect if you are airborne. Furthermore, all of your spells enjoy a quadrupling to Stagger Power during its execution. Therefore, regularly use Light Slash to remain afloat and unleash your chains of spells during Grand Impulse. This will rapidly push you toward a second stagger; although it is likely more efficient to stagger with a Heavy Slash in Schema 2, the Stagger Siphon auto-ability of L’automne is another reason why it is the ideal garb for this strategy. Use an elemental Potion immediately upon reaching the second stagger.
- Overclock Phase: Be persistent or Ereshkigal will reestablish its barriers; continue your assault to achieve the Level 3 stagger, using Bravery Feeder along the way. When this occurs, cast Deprotect, Imperil, and Poison. If the Unshelled effect of the Level 2 stagger has worn off, add Slow as well. Begin Overclocking and alternate between Attack and Light Slash to pile on the damage. You will likely need to refresh Poison (and potentially other ailments) after every Overclock. While doing so, trigger Transform Bravery, then Overclock again. Try to make one of these sessions coincide with the arrival of Meteor so as not to waste Overclock time.
- Awakening: By the time you run out of EP, Ereshkigal should already have used Awakening. If Battle Score is not a priority for you in this initial encounter, use an Ether and continue to Overclock to err on the side of caution. Regardless, prioritize refreshing Slow and Poison constantly. Even after Ereshkigal powers up, you will still be able to deal reasonable damage with Imperil and an elemental Potion in play. Use Bravery Feeder a second time when the enemy buffs again. Chip away at its remaining health to secure your victory; your Battle Time should range from three to three-and-a-half minutes. If you take much longer, you’ll be subject to Super Nova, which will likely necessitate the usage of a revival item. As long as you maintain Poison, however, Ereshkigal’s extinction is an inevitability.
The Lightning Returns: Final Fantasy XIII Complete Official Guide reveals the stats, hidden parameters, and ability list of Ereshkigal. It also offers the complete breakdown of the suggested Schemata setup which is used in the accompanying video.
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