The Void Beyond ??? AF or The Void Beyond Year Unknown is the first location of the fifth episode featured in Final Fantasy XIII-2, and the following walkthrough explains how to complete it.
Episode 5 is called Time in Motion.
The Void Beyond Year Unknown follows the events from the previous episode. We arrived here through Historia Crux, since this zone was unlocked before.
We already have the map of this area, but now we expect to encounter some resistance.
As soon as you reach the Void Beyond ??? AF a cutscene starts showing Caius. Seems like he was expecting us. After the cutscene, you will unlock a new achievement/trophy: Sooth Seeker.
When the cutscene ends, you will be able to play only as Serah. There is only one path to follow, at this point, so, move forward until you receive your first objective.
Objective 1: Who is that?
Move forward until you meet Yeul. Talk to her for a Live Trigger and you will get the Etro’s Sorrow Fragment.
Continue to follow Yeul and talk to her again for another Live Trigger and the Pulse’s Resolution Fragment. Check the cube in front of you and get Caiuss Sword.
Talk to Yeul for the third time and get the Lindzei’s Desire Fragment, and then find her again, downstairs. She will give you the Mwynn’s Tenderness Fragment.
Now, what you should do, is to go all the way up, without talking to Yeul. First, when you reach the top of the stairs, use Moogle to find the hidden Chocolina.
Get everything you need, because after you talk to Yeul for the last time, the boss fight against Caius, starts.
Return to Yeul and grab the Bhunivelze’s Sleep, then talk to her for the last time, but make sure you are ready to fight Caius.
Objective 2: Defeat Caius Ballad
We already know the strategy Caius uses, and we know that Noel will not participate in this fight.
For this boss battle, we have used the following formations, and tactics.
To remove Caiuss buffs, and maintain the health of our characters, we decided to go with a high level Saboteur unit, and Serah as a Medic.
A RAV/RAV formation helped us to stagger Caius; while the COM/COM formation allowed us to damage the boss.
Every time Caius attacked us, we switched to SAB/MED.
This time Caius seemed weaker than before, but his stagger bar filled slower.
After Caius is defeated, a cutscene starts and Serah wakes up in Episode 5 New Bodhum -00X AF-.