The walkthrough for Orphan’s Cradle is broken up into three parts. The first two sections cover everything up to Jabberwocky and Bandersnatch for Part 1 with everything up to the Tiamat Eliminator being covered in Part 2. The final battle is covered in this section, Part 3.
After defeating Tiamat Eliminator, you can use the warp portal to transport the team to the Narthex. As one final reminder, this is considered a point of no return. Head back to Part 2 of Orphan’s Cradle and review the checklist if you’re not sure whether there are parts you need to complete before venturing forward.
Use the 
Save Station up ahead and then wander down the hallways of the Narthex to find a Treasure Sphere that contains a vial of 
Ethersol. The final boss battle begins just up ahead, so let's take some time to review your party configuration, though there is nothing specifically that you need to protect yourself against. Still, it’s good practice to do one final review of the following:
Synergists) and debuffs (
Saboteurs) at the beginning of the fight.
Shield Talisman, Blessed Talisman, etc.)
Growth Egg and Collector Catalog. There will be no Crystogen Points (CP) awarded during this fight nor any spoils that can be influenced by whichever accessories you have equipped.Cherub’s Crown.Step through the doorway on the far side of the Narthex area when you’re ready to begin.
A lengthy cutscene will take place when your team first enters and then it’s time for the first battle which is against Barthandelus, one more time…
This version of Barthandelus is not nearly as difficult as some of the previous ones you have faced despite many of his attacks sharing the same names as those you’ve faced previously. He will use the following attacks:
In addition to the above, Barthandelus will cast regular laser-beam attacks on party members that hit for a relatively insignificant amount of damage. From an overall perspective, besides dealing with “Thanatosian Laughter” bringing your party member’s HP fairly low, the remaining attacks are not overly difficult to deal with.
Start the battle off by using 
Libra and use a paradigm that includes a Synergist and Saboteur like Evened Odds. You should aim to apply 
Imperil, 
Slow, 
Deprotect and 
Deshell on Barthandelus and keep those four status effects active for the duration of the fight.
You should also try to keep as many positive status effects active on your party members as you can utilizing both Evened Odds as well as Decimation to provide enough time for your Synergist to get them all active. Beneficial status effects for this fight include 
Haste, 
Protect, 
Shell, 
Bravery and 
Faith.
Depending on the strength of your party members, you may be able to defeat Barthandelus by ripping through all of his HP before a single Stagger wears off.
The team will take some time to celebrate too early before the next battle begins.
What a cool-looking final boss! With only one side of it having a wing, it's reminiscent of the one-winged angel from Final Fantasy VII (aka Safer Sephiroth). Orphan has a wide range of attacks that include the following:
Death. If this is used against your party leader, it can mean an instant game over screen. You can reduce the odds of this happening by equipping your party leader with a Cherub’s Crown, but for other party members, you may need to revive them from KO in the midst of battle.
Poison.Deprotect and Deshell which should be removed by having a 
Medic cast 
Esuna as quickly as possible. In addition to the attacks listed above, Orphan will do a standard physical attack that involves slapping all three party members.
The most important and difficult element of this fight is dealing with “Merciless Judgement”. Thankfully, this move is telegraphed ahead of time and you will know when it is coming up because it happens right after Orphan uses “Consummate Light” or “Consummate Darkness”.
Either way, because of the massive amount of damage inflicted on your party members, no matter what level they are, you should get in the habit of not letting their HP get too low during this fight and switching to a paradigm that includes a Medic.
The fight will begin with Orphan using “Merciless Judgement” right off the bat, so move into a defensive paradigm and don’t forget to use Libra early on in the battle. You should also ensure that you give a Saboteur enough time to get debuffs cast on Orphan including Imperil, Deshell and Deprotect and a Synergist should be casting Haste, Protect and Shell on your party members, too.
Other buffs, including Bravery and Faith, are also helpful along with a buff like 
Enfire which does increased damage with every attack if Imperil has been applied.
Orphan is resistant to many negative status effects buffs but it is susceptible to Poison which can be cast by a Saboteur. Unfortunately, if you have been using Fang as your Saboteur, she does not have access to this spell, but Lightning, Sazh and Vanille all do. While it’s not a deal breaker, if you do have access to this spell, it will inflict a large amount of damage on Orphan over the course of the battle, making the fight significantly easier (though it may need to be recast).
You may get unlucky and have one or more of your party members be instantly killed when Orphan uses “Progenitorial Wrath” (just revive them and continue along), but as the fight progresses, move into an all-out offensive and try to rip through as much of Orphan’s HP as you can while it is Staggered. Good luck!
The video below provides a demonstration on how to compelete this fight. Note though that it does not provide a demonstration of recieving a five-star battle ranking which is easier to do if you come back and re-attempt the fight later on after completing the end game content:
Another cutscene will take place at the end of the battle before involving Fang and Vanille before the rest of the team joins in, and then it is time for the final battle against Orphan’s true form…
Orphan will open the battle by casting Doom on your party leader just like you’ve seen before in the battles against the various Eidolons that you’ve fought throughout the game. Your goal is to defeat Orphan before the “4200” timer runs out otherwise it’s game over. This final version of Orphan can use the following attacks:
Fog and 
Pain on one party member.Haste, Bravery, Faith and 
Veil on Orphan. This move is only used after Orphan has been Staggered.
Begin the battle with a quick Libra and use your more defensive paradigm to load up Orphan with negative status effects (Deprotect, Deshell, Imperil and load your party up with positive status effects before moving into the all-out offensive.
Orphan will take very little damage in this form until you are able to trigger a Stagger, so the idea is to inflict as much damage as possible while it is Staggered and, ideally, you will be able to defeat it in a single Stagger if you time it properly.
Similar to above, this video provides a demonstration on how to compelete this fight but it does not provide a demonstration of recieving a five-star battle ranking. This is easier to do if you come back and re-attempt the fight later on after completing the end game content:
Congratulations, you’ve defeated Orphan and completed the story portions of Final Fantasy XIII! Now it's on to the optional side quest content!
Instrument of Change
You will automatically receive the Instrument of Change achievement / trophy at the conclustion of Chapter 13.
A lengthy cutscene will take place at the conclusion of the game. A few images are included below which have been taken from the cinematic that plays at the end of the game:
End game cinematic:
It’s now time to decide whether you want to work your way through the optional end-game content and challenge yourself to some of the more difficult battles that are available in Final Fantasy XIII.
The story mode tends to be fairly linear, but the truly entertaining sections of any Final Fantasy game, including this one, involve challenging yourself to the end-game content. If you’re interested in reading further, check out the end-game content section to get yourself started:
