Bandeau Pendu Analysis is a legendary drop from a Bandeau Pendu. You may have to kill them for a while until this material is found due to legendary bring the rarest tier in the game—it's represented by the color Orange. Bandeau Pendu Analysis, when exchanged with Kunad Highway Environment B, can get you one of the best gifts to give to Luka.
These pesky flying Others can be found from Phase 6 onwards in the Mizuhagawa District—Construction Site location. Finding them, however, can be a pain as you have to get to Floor 2 of the Construction Site, and it's not easy to navigate.
To get to the location they spawn, you have two ways to go. The first is to teleport to Mizuhagawa District—Yugiri Great Bridge. From the direction you load in, go forwards and enter the Construction Site. Keep to the left, climb the stairs, then go right, following the circle to where the save point is. Carry on, then take the first right you come to, and you'll encounter two Bandeau Pendu and two Plateau Pendu.
The second way is to teleport to the Construction Site. From there, keep to the left, and follow the circle, past the save point, to the lift ahead of you. But if you take a slight detour to the right, you can fight a few Bandeau Pendu here. Then after they are dispatched, that the lift down. This takes you down to floor 3. Climb the stairs to your right, and then go straight ahead to where you encounter the Bandeau Pendu.
Bandeau Pendu is also a hypersonic flying enemy, meaning you have to use SAS Teleportation from Luka or SAS Hypervelocity from Arashi to be able to attack them to ground them, so your party can help take them down. They have a low health pool, so killing them is not an issue.
To get them to respawn, teleport to another area that is not in Mizuhagawa District. Then teleport back to the Construction Site, kill them and rinse and repeat!
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