Final Fantasy XIII

"Galuf's Grail"

You must complete all 64 mark missions for this achievement.

Missions 45, 51, 55, 62, 63 & 64 were the most problematic for me, the rest I was able to beat pretty much immediately after finishing the story. My party for almost all of the missions was Light/Fang/Hope and I used a Fortisol and an Aegisol before all of these battles.

For missions 45 & 55 (both against Neochu's) I swapped out Light for Vanille so I could use her Death spell (Equipping her Belladonna wand increased the odds of Death working). The paradigm I used was Sab/Sen/Med. Both times I just repeatedly cast Death until it worked. I don't know how to affect the odds of it working, but I have killed Neochu's in 5 casts of Death and sometimes it has taken me 50+. Just be patient and it will eventually work. The difference between missions 45 and 55 is that in 55, the Neochu is accompanied by 5 Picochu's which all hit you for a little but of damage that really adds up (equipping items that boost physical resistance will really help here). If your party members get killed, just press start and retry. It took me about 5 tries, but on the 5th the Neochu died in less than 10 casts. Lastly, make sure to have a paradigm prepared to take out the Picochu's after the Neochu is dead. They are almost harmless without the major attacks from the Neochu damaging you.

For mission 51 (Attacus), you need to finish all 16 of the Faultwarrens mark missions (missions 35-50), which takes 6 run throughs of the Faultwarrens to complete A1-E6 on the Faultwarrens chart. After completing all of them, you can make one more run through and all of the D island (D1-D4) will have a new Cie'th stone that will take you to E7 where you can fight Attacus. Attacus cannot be staggered and is susceptible to Deprotect, Deshell, Slow and Curse. The key the this battle is having a Sentinel in your party. Twice throughout the battle Attacus will upgrade his sword to a more powerfull one and has the ability to kill someone in your squad with 1 blow if they are not a Sentinel and provoking him. This attack follows his "Concentrate" warning, letting you know when you need to make the switch to the paradigm with the Sentinel. Other than that, do the usual Com/Rav/Rav to get this chain gauge up and hurt him and he will go down eventually.

For mission 62 (against 2 Raktavijas), there is 2 major tips I can give. First, they are susceptible to Slow and Imperil. Second, they only use magic attacks. So equipping items with Magic Resistance will really help. I just equipped each of my party members with a maxed out Witch's Bracelet and didn't have much of a problem after that.

For mission 63 I swapped out Light for Vanille w\ a Belladonna Wand yet again. Equipping items with Earth Resistance will help a lot too. My paradigm was Sab/Sen/Med and I just cast Death until it worked. The Adamanchelid is the weakest Oretoise and it never took me more than 10 casts of Death to kill one. If you are really low level and are still getting killed by it's attacks even with the Earth Resistance items, you can also use your summon to take out it's legs so it cannot attack you. When you summon, immediately go into Gestalt mode and use your Y attack so you can get back to your party ASAP before the enemy stands back up. Keep casting Death and if the Adamanchelid stands up before you killed it, just restart and try again. It will eventually work.

For mission 64 (Vercingetorix), I used Light/Fang/Hope. My paradigms were:
Sab/Sab/Sab
Sab/Sen/Med (default)
Med/Sen/Med
Sen/Sen/Sen
Syn/Syn/Syn
Med/Med/Med (never had to use, but good to have just in case)
To start out I would cast Poison on the enemy and then switch to Combat Clinic (Med/Sen/Med) and just heal until he went into his invincible Impenetrable Auro ability. This is where you take the time to heal up if you need it and replenish your buffs with the Syn/Syn/Syn if you lost any during his Putrescence attacks. Then I switch to Sab/Sab/Sab and cast poison while the other 2 party members use Dispel to remove the buffs he gave himself, if the poison worked I switch to Med/Sen/Med and repeat everything I just explained, if not then switch to Sab/Sen/Med and cast poison until it hits then go to Med/Sen/Med and repeat. Somewhere around his 50% point, he will start using his Wicked Whirl attack that can wipe out your entire party. The second you see this, switch to your Sen/Sen/Sen paradigm and back to Med/Sen/Med after it hits to heal up. Do this and the Poison attacks should kill him in ~10 minutes!

Here's a link to a guide that shows the locations of all mission and their marks:
http://www.gamesradar.com/f/final-fantasy-xiii-cieth-stone-m...

Here's a link to a guide that has suggestions on how to 5-star all 64 missions:
http://www.ps3trophies.org/forum/final-fantasy-xiii/43019-5-...

Good luck on completing all 64 missions. :^D