Final Fantasy XIII

"Instrument of Faith"

You will receive this achievement upon completing Chapter 11. For those of you having troubles with the Boss (Barthandelus) at the end, I have written a base guide for you to follow that should help you defeat him.

Boss: Barthandelus
Approx. HP: 3.3 Million
Total Time to Defeat: 11:23
Doom: Nope... he did not have a chance to use Doom on me =)
More info: http://ff-13.info/barthandelus2nd/


Characters Levels/HP/Weapons

Lightning
COM: Level 4 (Maxed)
RAV: Level 4 - Helter Skelter Level 48
MED: Level 3 - 3543 HP

Hope
SYN: Level 3
MED: Level 4 (Maxed) - Airwing Level 26
RAV: Level 4 (Maxed) - 3360 (with HP boosting Accessories)

Fang
SAB: Level 3
COM: Level 4 (Maxed) - Glaive Level 35
SEN: Level 3 - 3750 HP

Paradigms:
Lightning/Hope/Fang
COM/SYN/SAB (Starting Paradigm)
MED/MED/SEN (Used when low HP to quickly Heal and get rid of Debuffs)
RAV/MED/COM (Used to build up stagger, while heal if needed)
RAV/RAV/COM (Used for quickly building Stagger when HP is high, and also to hit him hard when Staggered)

From looking at the Paradigms I used to defeat this boss, it is pretty straight-forward on what to use and when to use it. Now the rest is up to you to use them properly and to get the right timing. A good thing to keep in mind, this boss is really weak when debuffed, so don't be shy with using Fang as a SAB and Hope as a SYN to buff your party up. I also don't remember the exact name of the attack, but he will use a laser attack that does your party for some damage. So when he is going to use that, remember to quickly switch to your "Combat Clinic" Paradigm so help reduce some damage and heal quickly. I also don't recommend using your Summon until you are in a rough-spot or until near the end to quickly finish him off.

This is mainly just for a base-guide, so people can have a straight forward guide to help them get started. You do not have to use this exact method, but this is what I did and it worked perfectly. Just remember to do some Trial & Error, and you will get passed this guy, he isn't that hard and you will realize it when you pummel him =).

Hope this helped!

Good luck!

While you get the achievement for completely all of chapter 11, my guide is only going to help you with the most difficult part: the 2nd battle with Barthandelus.

First, you want to make sure that you party is Lightening, Fang, and Hope. You'll want to control Lightening. Fang is a BAMF, but she needs to be a Sentinel on her own. And while Hope is the best Medic, he can lay down some killer Synergist buffs much faster than you could. So, you'll want to be Light.

Your paradigms should be as follows (Lightening, Fang, Hope):
Relentless Assault (Rav, Com, Rav)
Delta Attack (Com, Sen, Rav)
Combat Clinic (Med, Sen, Med)
Aggression (Com, Com, Rav)
Mystic Tower (Rav, Sen, Rav)
Evened Odds (Med, Sab, Syn)
Set Evened Odds as your active paradigm.

As far as your Crystarium, you need to max out the stats for all three's top 3 roles (the ones listed in each paradigm). If you don't have them maxed out (which you should), you have to go grind it out to get them maxed, or you'll never make it through the fight.

When all of this is set up, then, and only then, are you ready to battle Barthandelus. Start off the battle with Evened Odds, which should be active right now. The first thing you should do is Libra.
Then you should just keep hitting Auto-Chain until Hope has cast 5 different buffs on everybody. When that happens, shift to Aggression. Hit Auto-Chain once (and only once). Shift to Relentless Assault, and Auto-Chain until he's staggered. Switch back to Aggression, and absolutely destroy the 3,307,500 (no typo) HP that he possesses.

You'll probably have to heal at some point during this. When that's the case, always switch to Combat Clinic. You'll heal really fast, and Fang will be able to use Mediguard, which helps with the healing process.

After the Stagger has subsided, you'll want to use 2 auto-chains of Aggression to start the process all over again, and then shift back to Relentless Assault. You can use Evened Odds throughout the battle, but as you near the end, you won't need it as much as you did in the beginning.

When Barthandelus' HP bar is about 3/4's empty, you'll want to start hitting RB. You'll notice that his HP is hovering above 900,000. Don't worry, it'll come down fast. The reason you're going to hit HP is because it lowers to threshold where the doom counter comes into play (without Aggression, it will pop in at about 600,000 HP; with, around 325,000). At this point, skip anything that's NOT Aggression or Relentless Assault. If you need to heal, use Renew (you should have 4 TP left, so you can use Renew twice). Once you stagger him after that doom counter comes up, you'll be able to finish him off rather quickly.

From here, to get the achievement, click on the Ci'eth Stone, then board the hovercraft. Watching the cut-scenes are optional.

I hope this helps. I know I was frustrated by not using Aggression, but believe me, it REALLY helps.

The above 2 guides are very detailed and great and I am only adding this VERY SIMPLE guide to show what worked for me.

After reading a few guides I found online as well as the official piggyback interactive guide, I just couldn't get him down fast enough with those strats before I got hit with doom. So I decided to wing it balls out.

He has no devastating attacks that can one shot you or even take a substantial amount of HP at one time which allowed me to go Relentless Assault > Combat Clinic.

I didn't have to heal that often either. My char's main roles were maxed but not because I chose to do it prior to the fight. I had been spending extra time grinding throughout all the chapters and it so happened I was maxed when I got to him. My party set up was Lightning/Fang/Hope.

Using this strat, I beat him before he even had a chance to cast doom. Maybe it was luck, but a win is a win.

Good luck.