The Assassin (アサシン, Asashin?) Class Card of the Fifth Ainsworth Holy Grail War was one of eight Class Cards transported to Illya's world in Fate/kaleid liner PRISMA☆ILLYA. As the Assassin fluctuates depending on the user, the version utilized by Shinji Matou produced a different Assassin, and it changed upon transferring worlds. Upon being utilized by Miyu Edelfelt, it changed yet again.
The maiden of poison possessed a body that is itself a cluster of poison and her own weapon.
Installing the card grants the user the ability to have every part of their body become highly poisonous as the access to Hassan of Serenity's Zabaniya: Delusional Poison Body is granted. No matter if it is their fingernails, their skin or even their breath, it becomes lethal poison. Droplets of sweat carried by the wind are enough to rob a target of their freedom and control of their own body.
The user also gains access to Hassan of Serenity's personal dirks, her white kunai-shaped daggers, used for both short-range and long-range combat.