Lol at the many inter-series matchups in the first rounds: Aria/Riko, Nagisa/Kyō, Mikota/Kurako, Yui/Ui, Shana/Hecate.
I'm not happy about having to choose between Nagisa and Kyō right away though. >_>;
ARENA 01: Iwasawa Masami
[Hasegawa Kobato]
ARENA 02:
[Tōwa Erio] Sakura Kyōko
ARENA 03:
[Makise Kurisu] Nakagawa Kanon
ARENA 04: Suzutsuki Kanade
[Charlotte Dunois]
ARENA 05:
[Eucliwood Hellscythe] Gasai Yuno
ARENA 06:
[Elucia de Lute Ima] Konoe Subaru
ARENA 07: Himeji Mizuki
[Kōsaka Kirino]
ARENA 08:
[Yui] Mikazuki Yozora
ARENA 09:
[Kirishima Shōko] Kuroi Mato
ARENA 10:
[Haqua du Lot Herminium] Aragaki Ayase
ARENA 11:
[Shimada Minami] Akemi Homura
ARENA 12: Irisviel von Einzbern
[Kashiwazaki Sena]
ARENA 13: Shiomiya Shiori
[Victorique de Blois]
ARENA 14:
[Gokō Ruri (Kuroneko)] Honma Meiko
ARENA 15: Nakamura Yuri
[Fear Kubrick]
ARENA 16:
[Kanzaki H. Aria] Mine Riko
ARENA 17: Haruna
[Yuzuriha Inori]
ARENA 18: Tachibana Kanade
[Kasugano Sora]
ARENA 19: Suiseiseki, Sōseiseki
[Fate Testarossa, Takamachi Nanoha]
ARENA 20: Izumi Konata
[Nagato Yuki]
ARENA 21:
[Louise Vallière] Nymph
ARENA 22:
[Illyasviel von Einzbern] Asahina Mikuru
ARENA 23:
[Ichinose Kotomi] Akiyama Mio
ARENA 24:
[Nakano Azusa] Kotobuki Tsumugi
ARENA 25: Hiiragi Kagami
[Sanzen'in Nagi]
ARENA 26: Sakagami Tomoyo
[Sengoku Nadeko]
ARENA 27: Suzumiya Haruhi
[Holo]
ARENA 28: C.C.
[Katsura Hinagiku]
ARENA 29: Fujibayashi Kyō
[Furukawa Nagisa]
ARENA 30: Shiina Mafuyu
[Aisaka Taiga]
ARENA 31:
[Last Order] Senjōgahara Hitagi
ARENA 32: Ikaros
[Saber]
ARENA 33:
[Misaka Mikoto] Shirai Kuroko
ARENA 34: Tōsaka Rin
[Index L. Prohibitorum]
ARENA 35:
[Hirasawa Yui] Hirasawa Ui
ARENA 36:
[Konjiki no Yami] Oshino Shinobu
ARENA 37:
[Shana] Hecate
ARENA 38:
[Sakakibara Kōichi, Misaki Mei] Miketsukami Sōshi, Shirakiin Ririchiyo