Tanya Degurechaff, a youthful soldier, is renowned for her predatory ruthlessness and remarkable tactical skill, earning the moniker "Devil of the Rhine." Beneath her harmless look lies a spirit that once confronted Being X, the self‑declared deity, in a contest of intellect—resulting in his rebirth as a small girl amid a realm of sorcerous conflict. Determined to rebel, Tanya vows to climb her nation"s military hierarchy as it gradually descends into global war, with only Being X standing as the greatest barrier to restoring the serenity she once cherished. Yet her keen judgment and battlefield initiative inadvertently drive the vast Empire toward becoming one of history"s most formidable powers.