Are you sure this is a reference to "The wrath of Khan"? They're all cosplaying characters from Code Geass, so I guess it's a reference to "Lelouch of the Rebellion".
Shizuki Hitomi
The new Knightmare FrameSakura Kyouko
The radiation wave equipped Anko Anko being the misreading of Kyouko's nameRegrets* scheduled for summer 2013
* I don't know if it's a pun or a typo, but there's written 後悔 (koukai, "regret") instead of the homophonic 公開 ("coming out")Akemi Homura
The quite energetic HomuraIn order to protect you, I will destroy the world---Madoka MagicaThe Wrath of Homuhomu Parallels the phrasing for the Japanese title of Star Trek II: The Wrath of KhanMiki Sayaka
The Law of the Cycles knight, Sayaka-chanTomoe Mami
Boob-suitKyubey
Orange