Whitll Wings

[Kira_88]

Does anyone happen to know where/what drops this Unit in Extra Mode? Also, how rare does it seem to be?

[Neith]

Deljabans drop it apparently, so I'd assume in a Hive mission.

[Kira_88]

S rank mission only I assume?

[Zorafim]

There are no rankings offline. Any deljaban can drop it with a really high drop rate. You should find it on your first or second run. Of course, you also need an S rank armor to equip it, but that shouldn't be a problem with your random perfect zero runs.