The value of a companion character in isekai lies not in their combat utility, but in what their dependency reveals about the protagonist. A YPS-3 Authority user like Beatrice operates on a plane of existence fundamentally detached from the YPS-2 Physicality of Filo, rendering a direct power comparison meaningless. Instead, the divide is found in their DNA profiles: Beatrice is a study in trauma, while Filo is a study in trust. Beatrice’s Growth is a psychological excavation, a struggle to reclaim an Ego that was crushed by centuries of waiting for a ghost. Her power is a cage that only opens when she accepts her own fragility through her contract with Subaru. In contrast, Filo’s Growth is a linear, biological ascent. Her perfect 100 in Growth represents the Shield Hero’s capacity to provide a safe environment for a creature of instinct to flourish. While Beatrice fights to move from a passive object of destiny to an active agent, Filo exists as a pure extension of Naofumi’s protective will. Beatrice’s Darkness—the moral and emotional cost of her immortality—creates a narrative weight that Filo’s instinctual innocence cannot match. Ultimately, the two characters represent the two poles of the loyal follower trope: one is a broken adult in a child's body seeking salvation, and the other is a growing child in a monster's body finding a home.