Here's another boss I can't really seem to find details of. I'll go based on what I can remember from the fight in JP.

Multiplayer Enemy AI by /u/TFMurphy

BOSS: Cid Raines (XIII)

Difficulties: 160 (Ultimate ) and 200 (Apocalypse)

Mastery Conditions:

• Win with 4 or more party members alive.
• Reduce Cid Raines' ATK.
• Reduce Cid Raines' MAG.

Overview:

• No elemental weaknesses or resistances here.
• His physical attacks are mainly single-target physical attack, or Combo, which hits random party members up to 4 times. He should also have an AoE single-hit physical attack too.
• For magical, he has Ruinga (AoE Non-elemental magic damage), Bioga (AoE Bio-elemental magic damage, chance to Poison), and Dazega (small AoE Non-elemental magic damage, chance to apply Sleep).
• He can also use Protect and Shell, which will reduce the damage you deal to him.
• At specific HP thresholds, he will use Seraphic Ray, which does AoE Non-elemental magic damage, and Dispels all buffs from your party. This is not an Ultimate Dispel, so it won't remove the likes of stat buffs. I believe the thresholds are roughly 70% and 40% of his HP respectively. It's an Ultimate Dispel, and will remove all stat buffs.

Tips:

• You will want to bring Sleep resistance here. Veteran players should have at least one copy of Crystal Ring (I), and two if they bought one from the last time the Greens shop sold accessories.
• You can dodge Seraphic Ray with a well-timed Magic Blink. Firion and Tyro will be stars here. Otherwise, have Hastega/Shellga/Protectga ready to be re-cast.
• Other than that, everything else is mainly standard tank and spank. Vaan and his Ark Blast will be relevant here as well, seeing as he mainly spams magic in his weaker phases.
• Gaia Cross can deal with his physical attacks, and Combo attack.
• Have one Dispeller so that you aren't walled by Protect/Shell.