From the Soul Calibur game series. Cosplayer is Giulia.
"For better or worse, this sword is my fate..." Isabella "Ivy" Valentine (イザベラ・バレンタイン - アイヴィー, Izabera Barentain - Aibī) is a character in the Soul series of fighting games. She appears in Soulcalibur,Soulcalibur II, Soulcalibur III, Soulcalibur Legends, Soulcalibur IV, Soulcalibur: Broken Destiny, Soulcalibur V, Soulcalibur: Lost Swords, and Soulcalibur: Unbreakable Soul. Since her first appearance, she has become one of the most recognizable and iconic characters in the franchise, mainly due to her snake sword, large breasts, revealing clothing, and silver hair. She is nicknamed "The Twisting Blade Of Solitude". (soulcalibur.wikia.com)