Guide
Round 1 - Titan
Immediately as the round begins, open tactical mode as Zack and cast Stop on Titan. This will prevent his barrier from rising.
Swap to Cloud and use ATB Boost to get 2 ATB bars. Hold square to move to Titan and when you reach him activate Prime Mode.
Switch back to Zack and gain an ATB bar by attacking Titan and when you do, swap back to Cloud.
Hold square to attack with Cloud and activate Prime Mode Fury (NOTE: This will be used for almost every round so get used to activating it). Once you have two ATB and Fury activated, cast Aeroga 3.
When Cloud is casting, swap back to Zack to gain more ATB while attacking Titan. As soon as Titan is pressured and out of Stop, re-cast Stop with Zack.
Swap back to Cloud and re-gain ATB and re-activate Fury. Cast Aeroga 3 again once you have two ATB. This should stagger Titan.
Gain two more ATB with Cloud and re-activate Fury if necessary. Re-cast Aeroga 3 and Titan should be defeated.
Note: Titan is still relatively easy even if he gets his shield up at the start. Don't despair. Have Zack cast Faith on Cloud and use mostly the same strategy with Cloud of ATB -> Fury -> Aeroga 3 and Titan will be down in no time.
Round 2 - Hueyacoatl
Swap to Cloud, move to the right slightly and activate ATB Boost. Activate Prime Mode. Hold square to build two ATB and gain Fury. Activate Aeroga 3.
Swap to Zack while Cloud is casting, hold square to gain ATB.
Hueyacoatl will rise to the air, use Supercharged and become pressured. Make sure you don't get hit by Supercharged. Onc the lands, cast Stop on him with Zack but make sure he has landed first.
Swap to Cloud, hold square to attack to gain ATB and activate Fury. Once you have two ATB, cast Aeroga 3.
Swap to Zack while Cloud is casting (do you see the trend already?), build two ATB and dash away. Use Stop again (make sure the enemy is on the ground). Then use Faith on Cloud.
Swap back to Cloud, build two ATB and activate Fury. Then Aeroga 3 to end the fight.
Round 3 - Phoenix
This should be relatively easy as all of the fire attacks from Phoenix should heal Cloud.
Swap to Zack and cast Faith on Cloud.
Swap to Cloud and manually gain two ATB charges. Activate Prime Mode and hold square to gain Fury. When Phoenix summons an enemy, destroy it with Aeroga 2.
Hold square to attack Phoenix and keep Fury activated. Rinse and repeat until Phoenix starts casting Breath of Creation which indicates it's about to summon a monster. As soon as Bomb is summoned, destroy it with Aeroga 2.
Again rinse and repeat until the next the Grand Horn is summoned, use Aeroga 2.
As soon as Grand Horn is defeated, use ATB Boost to go to two ATB immediately. Use Blizzaga 3 on Phoenix (swap to Zack to gain ATB/do damage while Cloud is casting). This should stagger Phoenix.
Re-activate Fury on Cloud and do another Blizzaga 3 when you have two ATB and this should defeat Phoenix.
Round 4 - Brineborn Demon
Immediately swap to Cloud and dash away. Activate ATB Boost. Cast Firaga 3. This will pressure Brineborn Demon.
Swap to Zack and cast Stop.
Swap back to Cloud, activate Punisher Mode, hold square to activate Berserker. Keep spamming square to build two ATB. Cast Firaga 3.
Swap to Zack, build one ATB.
Swap back to Cloud, open tactical mode, cast Faith on Cloud with Zack. The Firaga 3 should now Stagger Brineborn Demon.
Use Punisher mode, re-acitvate Berserker, gain two ATB and finish him off with Firaga 3.
Round 5 - Kujata
Cast Faith on Cloud with Zack.
Swap to Cloud, dodge, use ATB Boost and activate Prime Mode. Start building ATB with Cloud. If Kujata is about to use Ferocious Lion, dash away from him to avoid it. If he is about to use Thunderous Stomp, start spam dashing out of the way.
The idea is to keep building two ATB with Cloud and when Kujata is about to summon a Crystal, cast Aeroga 3 on him. This will temporarily stop him and stop the Crystal from spawning. You can tell when he is about to summon a Crystal as he will scream into the air to summon it.
Rinse and repeat to defeat Kujata.
Note: If you don't manage to stop the Crystal, don't panic. Keep spamming Aeroga 3 on him regardless (with Faith + Fury) and you will eventually defeat him. Sometimes he will get a Fire/Ice Crystal and start healing you, allowing you to easily spam Aeroga 3.
Round 6 - Iron Giant
The primary objective of Iron Giant is to avoid getting hit! Stay behind him and dodge his attacks. He will heal Cloud with his Firaga so don't worry about that. If you aren't worried about time, you can cheese this fight by staying away, build ATB and casting Aeroga 3 to keep your MP.
Cast Faith on Cloud with Zack.
Swap to Cloud, use ATB Boost, activate Prime Mode. Attack Iron Giant and activate Fury. Rememeber, stay behind him when possible. He does have a backswing attack that can hit you when behind him so watch out for that. Cast Aeroga 3 when you have two ATB.
Rinse and repeat this strategy to defeat him. Iron Clad is weak to Lightning if you want to cast that but it will drain your MP. If you want to play it safe, stick to Aeroga 3.
Round 7 - Alexander
Cast Faith on Cloud with Zack.
Swap to Cloud, activate ATB Boost, move to the right arm and activate Prime Mode. Activate Fury while building two ATB. Avoid any attacks where needed. When you have two full ATB (and Fury activated), cast Thundara 2 on each Arm to destroy them instantly. This will pressure Alexander.
Get in snug behind Alexander, build two ATB while in Prime Mode to keep Fury activated. Cast Aeroga 3. Do the same thing again and the second Aeroga 3 should stagger Alexander.
Once staggered, do the same thing again (two ATB - Fury), cast Aeroga 3 again to finish him off.
NOTE: If you see Alexander using Homing Beams at any time during the fight, then start dashing to avoid them. They will kill you!
Round 8 - Mindflayer
Cast Faith on Cloud with Zack.
Build more ATB with Zack and cast Manawall on Cloud. This is to avoid possibly dying to Eldritch Horror from the Mindflayer.
Swap to Cloud, activate ATB Boost, activate Prime Mode. Build ATB + Fury. Cast Aeroga 3. This is mostly a rinse and repeat from here.
If you are feeling paranoid, keep Manawall up on Cloud at all times.
When Mindflayer activates Telekenisis, you can still attack him for a few more seconds before moving to hide behind one of the rocks. If you have the ATB, as soon as Mindflayer starts casting Psychotic Break, you can cast Aeroga 3 to break him out of the animation and stop the cast. If you are worried, just hide behind the rocks.
Round 9 - Bahamut Arisen
Cast Faith on Cloud with Zack.
Swap to Cloud, dash away, use ATB Boost and Prime Mode. Most of Bahamut's attacks are easily blockable so make sure your timing is right. You can also use Counterfire (R1+ X) to block most of his projectiles (Nova Bomb, Flame Breath) without taking damage. Try avoid Crush Grip if you can but if you do get grabbed by it, swap to Zack and build ATB and then cast Manawall on Cloud.
When Bahamut starts casting Particle Charge you need to make sure Cloud has two ATB (preferably before Bahamut starts casting this, so save your ATB where possible). Use Aeroga 2 on each of Bahamut's wings to destroy them (if you have Faith). This will pressure Bahamut.
Make sure you are in Prime Mode, build two ATB and activate Fury. If he is still pressured, activate Aeroga 3 to get some damage in.
When Bahamut transforms, block his attacks. You will take damage but try not to panic as your Aeroga will heal you later. Try to keep two ATB on Cloud to prepare for the next Particle Charge from Bahamut. When he starts casting it again, destroy the two wings again with Aeroga 2.
It's mostly a rinse and repeat from here on out until Bahamut is destroyed.
When staggered, build two ATB with Cloud and activate Fury. Use Aeroga 3 to try finish him off.
Round 10 - Odin
Cast Faith on Cloud with Zack.
Swap to Cloud, use ATB Boost and activate Prime Mode. Start to build ATB with Cloud but be careful to avoid getting hit! The more you get hit by Odin, the faster you will activate Zantetsuken. If you are confident in your blocking abilities, you can block his attacks while in Prime Mode.
As soon as you have two ATB, cast Aeroga 3. When Zack has an ATB bar, cast Manawall on Cloud.
Keep this up while maintaining decent pressure on Odin and you should stagger him relatively quickly.
When staggered, use the usual combo of Fury -> two ATB -> Aeroga 3.
When Zack has an ATB, refresh Manawall on Cloud.
Odin should be almost defeated by now, but don't rest yet. I've lost twice to Odin when he was at roughly 2% and 5% HP!
Odin will use Spatial Distortion, make sure you are on the correct side. Once he has finished casting it, swap back to Zack as Odin is about to cast Temporal Imprisonment. This will ensure that Zack gets captured and not Cloud. Note: If you have a Limit Break available then this part is super easy, when Odin is about to cast it and lowers his sword, activate the Limit Break. This will make you completely immune to the Imprisonment and keep your two characters. If you are following this guide exactly however, you most likely won't have your Limit Break available.
Swap back to Cloud and build ATB. Avoid out of Ring of Hellheim if it is cast. Build two ATB and cast Aeroga 3 to hopefully end the fight. Play a bit cautiously here if you need to and don't get hit casting Aeroga 3, make sure you are safe to cast it.
