This is my pick for the most straightforward way to win this stage. You don't even need a Green Terra for this to work.
This team works really well because Terra can easily take many many consecutive turns with her LD, and this also prevents the bosses from getting any turns even when they Cut in Turn Order
Timestamp
Party Setup at 5:57
Cissnei is having 5/5 UW and Terra has a 1/5 UW
If you don't have Xande LDCA, give Cissnei a Enna Kros LDCA.
Raijin LDCA on Terra is really optional. If you don't have it just give her your best DEF down or HP DMG Up call.
0:00 Setup
Reset until Auron goes first. Use both Raines call and LD then swap to Garnet and use BT+. This brings the orb to 2-count.
Pop Summon
1:32 Summon Mode
Garnet use S2
Cissnei use AA
Cissnei use Xande LDCA
Cissnei use LD
Terra use LD
Thaaaats pretty much it. Just LD meltdown spam until the end, use BT mode if you want.