Update was released in Japan the other day, and we now know what all the costumes are (source):
Hyrule Warriors Master Quest pack
Twilight Princess pack
Majora's Mask pack
Ganon pack
Hyrule Warriors Master Quest pack
- 1 new scenario
- 1 new weapon - Epona
- New adventure map
- 2 costumes - White costumes for Cia and Lana
Twilight Princess pack
- 1 new character - ???
- 1 new weapon - ???
- New adventure map
- 2 new costumes - Gothic Agitha, Maskless Zant
Majora's Mask pack
- Two characters - ???
- New adventure map
- 3 costumes - Darmani's Ghost Darunia, Lulu Ruto, (Hilda Zelda or Purple Link?)
Ganon pack
- 2 new game modes