"A message posted on the WCG Iran Facebook page said the Iranian government demanded that the characters Ahri, Akali, Ashe, Caitlyn, Cassiopia, Diana, Elise, Evelyn, Fiora, Irelia, Janna, Karma, Katarina, Kayle, Leblanc, Leona, Lissandra, Lulu, Lux, Miss Fortune, Morgana, Nami, Nidalee, Oriana, Quinn, Riven, Sejuani, Shyvana, Sivir, Sona, Soraka, Syndra, Tristana, Vayne, Vi, and Zyra - all females - be banned from tournament play. The characters Diana, Fiora, Karma (only traditional skin), Kayle, Leona, Lissandra, Lulu, Lux, Nami, Quinn, Sejuani, Tristana and Vayne are being considered for inclusion."
Source: http://www.escapistmagazine.com/forums/read/7.826770-League-of-Legends-Tournament-Characters-Banned-By-Iran