"Yusei loses something precious to him." Fusion with Supernatural. Treasonshipping. WARNINGS: Graphic depictions of blood, violence and sex. Bondage. Bloodplay. Dubcon.

In which, Agent Masumi Koutsu (Code name: Gemknight) infiltrates a high-profile ball and looks gorgeous in a cocktail dress. Then a gang of super criminals crash the party. A companion fic to "Assemble! Yu-Tagonists", featuring the kickass female characters of the entire Yu-Gi-Oh! series. Also includes: an actual plot! (maybe)