The Cursed Twin Blades of Vengeance are the ninja weapons used by the mutant Alopex and objects from the series "Teenage Mutant Ninja Turtles".
The blades were created years ago by twin sisters. They used them to get revenge on an evil warlord who slayed their family. Since then, the blades cursed anyone injured by them, doomed to face death at every opportunism. Eventually they were recovered and brought to a museum in New York City.
A fox-mutant named Alopex stole them to use on her brother Tiger Claw, but when Raph and Casey tried to stop her she cursed Casey with one of the blades.
When April, Casey and the Turtles asked her to help lift the curse, she told them the only way to reverse the curse was for Casey to use the blades to against her or destroy them.
The blades curse anyone cut by them with fatal misfortune. Even the smallest wound can equal death. The only way to remove the curse is to destroy the steel or use them on the one who inflicted it, passing it to them.