Reactor Purge (リアクターパージ Riakutā Pāji) is the ultimate defensive function of Nanoha Takamachi's Barrier Jacket. When the damage taken by Nanoha exceeds her Jacket's limit, it will "detonate" to counteract a single attack, similar in principle to reactive armour on modern tanks. It is cast in the first battle of A's against Vita's Raketenhammer. Reactive Purge (リアクティブパージ Riakutibu Pāji) is the same function of Subaru Nakajima's Barrier Jacket, as shown in the combat against Cinque. Likely, the function is also loaded to the Barrier Jackets of other Riot Force 6 Forward members.