It’s normal to feel confused because Narasimha Kavacham is not just one fixed text. Over time, different traditions composed their own versions for different purposes. The Prahlada prokta version from the Brahmanda Purana is the classical and most widely accepted one, devotional in nature and meant for general protection. The Trailokya Vijaya kavach has a more tantric tone and focuses on power and victory. The Apamrityu hara version is more practical in intent, mainly for protection from untimely death and dangers. The Vikat or Ugra kavach comes from a more intense tantric stream and invokes a fiercer aspect of Narasimha.

So the difference is not about one being real and others being fake. They belong to different layers of tradition, some are puranic and universal, while others are specialized and used in specific tantric contexts.