Board Thread:Episode Discussions/@comment-25319479-20160407114523/@comment-3279282-20160407190258

さらに (Furthermore) 両目に (in both eyes) “万華鏡写輪眼”が (the "Mangekyo Sharingan" is) 揃う (present) ことで (being the circumstances) 現出する (appears) “須佐能乎” ("Susanoo").

Japanese is the easiest to understand by reading the sentences backwards:

Susanoo appears if the circumstances are that the Mangekyo Sharingan is present in both eyes.