Before you go, open your menu and spend some Crystarium Points to unlock Steelguard in Sentinel role for Fang because you'll need for 2 or 3 battles ahead.

There are 2 battles and 1 item behind you.

• ENEMY (E-01): Vespid Soldier (x3)
• ENEMY (E-02): Viking (x1), Vespid Soldier (x2)
• ACCESSORY (T-01): Whistlewind Scarf (x1)

Continue on the main path.

• ENEMY (E-03): Vespid Soldier (x3)
• ENEMY (E-04): Vespid Soldier (x2)
• ENEMY (E-05): Viking (x1), PSICOM Dragoon (x2)
• ITEM (T-02): Perfect Conductor (x1)
  (At the corner of the far right section)
   
• ENEMY (E-06): Viking (x1), PSICOM Dragoon (x2)
• ENEMY (E-07): Deckdrone (x3), Vespid Soldier (x2)
• ENEMY (E-08): Deckdrone (x7)
  (This is another stupid battle where you'll 99% die when all Deckdrones use Tornado kick at same time, just summon Odin when you see they are about to use Tornado Kick. Another strategy is that you can use Fang's Sentinel role to tank the damage (switch between COM/MED/SEN and COM/RAV/SEN), but you'll have unlock Steelguard first from her Crystarium)
   
• ENEMY (E-09): Vespid Soldier (x1), Deckdrone (x5)
  (Use COM/MED/SEN and COM/RAV/SEN if you have a hard time in this battle)

There is a path to your right that look like a blade on the map.

• ENEMY (E-10): PSICOM Dragoon (x2)
• ITEM (T-03): Barbed Tail (x13)

Backtrack to the main path.

• ENEMY (E-11): Deckdrone (x5)
• ENEMY (E-12): Viking (x1), Deckdrone (x3) (LAST ENCOUNTER)
• ENEMY (E-13): Viking (x1), Vespid Soldier (x2) (LAST ENCOUNTER)

You may have noticed 3 thrusters in this area, near the last Thruster is an item at the lower level. Fortunately, you can use the thruster as a ramp when it lowers.

• ITEM (T-04): 300 gil
• ENEMY (E-14): Viking (x1) (LAST ENCOUNTER), PSICOM Dragoon (x3)
• ENEMY (E-15): PSICOM Dragoon (x4)
  (Use COM/MED/SEN and COM/RAV/SEN, these guys only attack Hope)
   
• ACCESSORY (T-05): Spark Ring (x1)
• ENEMY (E-16): PSICOM Dragoon (x2)

It's time to spend your CPs again in order before a boss fight.

• Lightning: Ravager, Commando, Media
• Hope: Synergist, Ravager, Medic
• Fang: Commando, Saboteur, Sentinel
• Snow: Sentinel, Commando, Ravager

Paradigm (Lightning/Hope/Fang):

• MED/SYN/SAB (default)
• RAV/RAV/COM
• COM/RAV/COM
   
• BOSS (B-01): Kalavinka Striker (x1)
  Strategy: 
  • Cast 1 Libra.
  • Start with MED/SYN/SAB until Hope casted Protect/Shell/Veil and Fang casted Slow/Imperil, switch to RAV/RAV/COM and COM/RAV/COM. You should be able to finish it in one Stagger
     
• BOSS (B-02): Kalavinka Striker (x1)
  Strategy: The strategy is pretty the same as the first phase, except that you don't need to use Libra this time. One thing to note though, the boss is stronger, especially with his "HellStorm Bolt" attack. But once, Hope casted Barthunder on everyone, you shouldn't have any problem.

Finally, you are able to re-arrange your party members but I suggest you keep the same lineup for now.

Let's activate the switch in front of you and move forward.

• ENEMY (E-17): PSICOM Infiltrator (x3), PSICOM Destroyer (x1) (FIRST ENCOUNTER)
  (Always kill PSICOM Destroyer first in any battles, because he deal so much damage)

Okay! Open your map you'll see platforms both sides and front. These platforms have 3 switches that lead to one another. In other words, when you activate all switches, they will create 3 paths, left, middle, and right. Let's make it simpler, Activate the left and go to the left path.

Left path:

• ITEM (T-06): Librascope (x1)
• ACCESSORY (T-07): Pain Dampener (x1)
• ENEMY (E-18): PSICOM Destroyer (x1), PSICOM Dragoon (x3)
• ITEM (T-08): 3600 gil
• ENEMY (E-19): Thermadon (x1), PSICOM Destroyer (x1), PSICOM Infiltrator (x3) (LAST ENCOUNTER)
• ACCESSORY (T-09): Gold Bangle (x1)

Middle path:

• ENEMY (E-20): PSICOM Reaver (x1) (FIRST ENCOUNTER), PSICOM Dragoon (x4)
• ENEMY (E-21): Thermadon (x1), PSICOM Raider (x2)
• ENEMY (E-22): PSICOM Huntress (x2), PSICOM Destroyer (x1), PSICOM Reaver (x1) (FIRST ENCOUNTER)

Right path:

• ENEMY (E-23): Thermadon (x1) (LAST ENCOUNTER), PSICOM Destroyer (x1)
• ACCESSORY (T-10): Rune Bracelet (x2)
  (Right turn - need to activate a switch)
   
• WEAPON (T-11): Umbra (x1)
• ENEMY (E-24): PSICOM Dragoon (x2) (LAST ENCOUNTER, PSICOM Raider (x2) (LAST ENCOUNTER), PSICOM Reaver (x1) (LAST ENCOUNTER)
• ENEMY (E-25): PSICOM Destroyer (x2) (LAST ENCOUNTER), PSICOM Huntress (x1) (LAST ENCOUNTER)
• ITEM (T-12): Perfect Conductor (x1)

Once you are done, go to the yellow mark. You may have to fight the enemies in the middle platform again.

• ITEM (T-13): Ethersol (x1)

Save your game and prepare for a boss fight. He is probably one of the hardest boss you'll ever fight.

Paradigm (Lightning/Hope/Fang):

• RAV/RAV/COM (default)
• RAV/MED/COM
• RAV/SYN/SAB
• COM/RAV/COM
• MED/MED/COM
   
• BOSS (B-02): Barthandelus (x1), Right Pauldron (x1), Right Ailette (x1), Left Pauldron (x1), Left Ailette (x1)
  Strategy: 
  • Just like any bosses with multiple parts, use 1 Librascope to get full intel, then destroy his parts first before you focus on the main body. 
  • You should start wtih RAV/RAV/COM (switch between RAV/MED/COM when you need healing) to take out both Pauldrons (x2) and Ailettes (x2). 
  • Once all of his parts are destroyed, switch to MED/SYN/SAB until you get both Protect and Shell from Hope.
  • Now it's time for offensive, switch between RAV/RAV/COM and RAV/MED/COM for staggering and healing. When he is staggered, switch to COM/RAV/COM for full damage.
  • There is one attack you have to watch out "Destructo". This attack can wipe out your entire party and remove "stagger" but it takes time to charge. To reduce the damage from this attack, you have to keep attack him when he is charging. So, whenever you see "Destructo" on his head, immediately, switch to RAV/RAV/COM until you hear him groan (you can also see him stunned from the animation). Also, make sure that your health bars are full, if not, switch to MED/MED/COM after the groan.