The contract between these two represents the synthesis of static despair and active agony. While Beatrice possesses the raw arcane output of a YPS-3 entity, her centuries in the Forbidden Library were defined by a total collapse of Ego, transforming her power into a gilded cage of waiting. Subaru operates at a YPS-4 strategic level, yet this influence is bought through a Darkness score that dwarfs Beatrice's, paid in the currency of repeated death and psychological erosion. The comparison breaks down if viewed as a traditional power dynamic because their utility is symbiotic rather than additive. Beatrice provides the magical ceiling Subaru lacks, but Subaru provides the narrative momentum Beatrice lost. Her Growth is a reaction to his persistence; she moves from a state of frozen grief to active agency only because Subaru refuses to let her remain a relic. Their bond is the only mechanism in the series that converts Subaru's trauma into a tangible, lasting victory for someone else. By linking their fates, the story argues that the only cure for a centuries-long wait is a partner willing to die a thousand times to end it. This transforms their relationship from a mage-contractor pairing into a mutual rescue mission where the cost of survival is shared.