Hemalurgic Decay

Hemalurgic Decay emerges as a critical flaw in the Mistborn series' magic system, revealed in The Hero of Ages as an intangible force that progressively weakens stolen Allomantic and Feruchemical powers each time a Hemalurgic spike is transferred between hosts. This decay ensures that no spike retains full potency beyond its original creation, imposing a fundamental limitation on Ruin's ability to mass-produce efficient Inquisitors and other Hemalurgic constructs. Though not explored in later books, it underscores the imperfect nature of Hemalurgy, balancing its raw power with inevitable entropy.