The idea behind here is to go Cid Highwind EX three times in a row to blitz both bosses dead.
Setup
Party 1
Cid Highwind, FR 20, 5/5 UW, Prishe LDCA
Laguna with BT+, Kurasame LDCA. Kurasame LDCA isn't important. Can be swapped for any other call
Lunafreya LDBT, FR 30, 5/5 UW, Raines LDCA
Raines call can be swapped for Onion Knight
Party 2
Sherlotta, FR30, 5/5 UW, Cyan LDCA
Sherlotta can be swapped with another Supercharger such as Krile, Braska or Penelo. Cyan LDCA can be swapped with something like Yda.
Iroha, FR30, Ashe LDCA
Ashe LDCA isn't important. Iroha is there only to press FR
Auron, FR10, Raijin LDCA
Raijin call is quite important to help you avoid Absolute Zero when Dullahan hits 79%
Auron himself isn't too important. You can swap him with virtually anyone else. Preferably someone who also starts with an instant turn.
Timestamp
0:00 Walkthrough of Setup
6:29 Battle Start, Luna charging
Reset until turn order is Laguna, Luna and Cid
Laguna sets up Desperado
Luna swaps to Auron for the debuffs before swapping back. Also swap to Sherlotta for Cyan LDCA damage midway through. Beyond that it's a rotation of LD into attacks and using S1 to help charge FR and heal herself. Use Raines LDCA to pull Laguna back.
12:26 Finishing setup
Laguna's next turn is to bring Dullahan to exactly 80% before swapping out to Iroha
Use Iroha FR to bring Dullahan to 79% and trigger Absolute Zero
Then swap her for Sherlotta, use S1 until there's 4 turns of FR time remaining and then swap to Cid
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