Adult Mode (おとなモード Otona Mōdo) transformation is a shapeshifting-like magic that allows an underage caster to transform their body into an adult (or rather, late teen) form of themselves and back. The primary advantage of the Adult Mode is the apparently greater capacity of an adult body for magic channeling, compared to a child. Therefore the Adult Mode is primarily used for training, especially involving physical exercises, e.g. in Strike Arts and Kaiser Arts. It can be also used, however, to conceal the caster's identity.
|Armed Form||Ancient Belka||Einhard Stratos|
|Powered-System||Modern Belka||Rio Wesley|
|Transformation Mastery||Modern Belka||Vivio|
- In StrikerS, Jail Scaglietti and Quattro forcibly transformed Vivio into her "Sankt Kaiser Mode" (聖王モード), the original idea of this spell, by infusing her with a Relic. She was only able to revert back to her child form when Nanoha Takamachi destroyed the Relic within her.
- It may also be seen that Caro Ru Lushe uses a spell with the inverse effect (Dragon Soul Summon) on her summoned dragon Friedrich to seal his powerful adult form, allowing him to stay with her. This is probably similar to how familiars and Unison Devices stick to small forms in order to minimize their mana expenditure.