True power in the isekai genre is often defined not by its application, but by its suppression. Because one operates via physical devastation and the other via systemic authority, a direct YPS comparison is functionally meaningless, despite both occupying the YPS-5 tier. The real divergence is found in the DNA profile, specifically the Ego dimension. Diablo transforms his identity into a tool for Rimuru, channeling his primordial nature into the role of a butler. This is an act of self-determination; he chooses the collar. In contrast, Mile exists in a state of perpetual erasure. Her struggle to remain "average" is not a choice of devotion but a desperate attempt to avoid the isolation that comes with her cosmic misalignment. While Diablo uses his status as a continent-level entity to curate a world for his master, Mile treats her similar capacity as a liability to be hidden. One finds liberation through a specific, obsessive bond, while the other finds a cage in her own success. The narrative function of YPS-5 power here shifts from a weapon of war to a psychological weight: for the primordial, it is the price of admission to a meaningful relationship; for the reincarnated girl, it is the wall that separates her from the humanity she craves.