|Race||Devil/Vampire hybrid (Low-ranked)|
|Hair Color||Platinum blonde|
|Equipment||Forbidden Balor View|
|Affiliations||Kuoh Academy (First-year student)|
Occult Research Club
|Ranking||Bishop (Mutation Piece)|
Gasper Vladi (ギャスパー・ヴラディ Gyasupā Vuradi?) is a cross-dressing, half-vampiric female who first appears in Volume 4 of the light novels. Her Sacred Gear, "Forbidden Balor View" (停止世界の邪眼（フォービドウン・バロール・ビュー） Fōbidoun Barōru Byū?, lit. "The Evil Eye that Stops the World"), has the ability to stop the time of those she sees but is unable to control it. As a result, she is sealed by Rias as ordered by the elders prior to the series until he has grown up enough to control it. She still shows a lack in full command of his power, but can significantly improve a lot by drinking Issei's blood (as a result becoming very attached to the latter). Gasper is a coward and prefers to shut herself in. She also has a penchant with boxes, and is always seen carrying one. Being a half-vampire, Gasper has the ability to command bats, which she uses for reconnaissance.
Gasper is a child of a Vampire Lord and a human woman, and thus is hated by many of her own clan, including her siblings, mainly due to her Vampires discriminating which is stronger than the other races. Eventually, she was chased out of her house and was targeted by vampire hunters, later losing her life. It was around that time Rias found her and took pity in the girl, reincarnating her into a Devil through a use of a Bishop Mutation Piece. In Volume 11, Gasper goes to the Grigori headquarters to increase her powers. She returns in Volume 12, disappointed that she gained nothing until she heard about Issei's death from Georg, causing Gasper to undergo a change where she can create an enormous amount of darkness that devours everything (even the mist created by Dimension Lost), which allows her to defeat Georg.