Modernist drama between 1914 and 1945 underwent a process of rejuvenation through the remarkable revival of the medieval mystery play in women's writing on war. The adaptation of the allegorical mode of medieval drama allowed female authors to comment on political conflict, national identity, and the shifting of gender roles from a combined perspective of the inherently personal and the global. This article investigates how Vernon Lee, Mina Loy, and Else Lasker-Schüler, three authors working across the turn of the century and across various nations, remodeled the form into personal manifestos of cosmopolitan authorship. Lee's Satan the Waster (1914/20), Loy's The Sacred Prostitute (1914), and Lasker-Schüler's IchundIch (I and I, 1940/41) expose the dual status of the poet as performer and critic of their own time. The allegorical capacity of these plays allows them to ironize and criticize the idea of rigid boundaries, be these historical, national, or gendered. As these authors demonstrate, the destabilizing of boundaries common to decadent, performative writing was developed and adapted in modernist avant-garde writing.