A lethality device includes a penetrator structure configured to penetrate a target and an incendiary material disposed near the penetrator structure. The incendiary material self-ignites and is injected into the target after penetration of the target. A projectile includes a penetrator structure configured to penetrate a target, an incendiary material disposed near the penetrator structure, and one or components other than the penetrator structure and the incendiary material disposed aft of the penetrator structure. Loads from the one or more components are transferred to the penetrator structure upon impact with the target. The incendiary material self-ignites and is injected into the target after penetration of the target. A method for defeating a target containing an ignitable material includes broaching or puncturing an outer skin of the target, self-igniting an incendiary material, injecting the ignited incendiary material into the target, and igniting a material disposed within the target.