Bat Within

Bat Within is a defensive dark arts technique from the Bayonetta franchise. First appearing in the game Bayonetta, Bat Within is one of the four abilities that Umbra Witches can use to transform themselves into animals, the other three being Panther Within, Snake Within, and Crow Within. In its appearances, Bat Within has a consistent function in that it is used to avoid attacks at the last second possible.

Bayonetta
In Bayonetta, Bat Within is an ability that is available for purchase at the Gates of Hell once the Beast Within ability in Chapter VII has been unlocked. It can be purchased for 30000 Halos. Once purchased, it is activated by dodging at the very last moment before an attack. If it is successful, Bayonetta briefly turns into several bats and quickly reforms, typically activating Witch Time immediately afterward. Certain enemies, such as Gracious and Glorious, cancel out the Witch Time that occurs following the technique. The Bat models of Bayonetta are available in the gallery upon defeating the game.

Bat Within appears in a cutscene in which Bayonetta is avoiding Jeanne's barrage of bullets.

Bayonetta 2
In Bayonetta 2, Bat Within is available for purchase at the Gates of Hell immediately after the Prologue chapter for 30000 Halos. Bat Within functions identical to the first game and the Bat models are once again available to view in the gallery.

The move appears in a cutscene when Bayonetta rescues Loki from the Masked Lumen.

Super Smash Bros. for Nintendo 3DS / Wii U
In Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U, while it is not a standalone special move, Bat Within activates if Witch Time is activated too late, or if Bayonetta dodges an attack at the last second, like in the series itself. By activating Bat Within, Bayonetta can move in the direction the player tilts the control stick, except if Witch Time was activated. Witch Time can still activate when Bayonetta is hit between the activation windows for both it and Bat Within, although this slightly shortens the duration of Witch Time if this occurs. Bat Within also halves the damage Bayonetta took, rather than completely negating it.

Super Smash Bros. Ultimate
Bat Within reappears in Super Smash Bros. Ultimate, retaining its functionality from the previous game.

In the intro cutscene to World of Light, Bayonetta uses Bat Within to evade some of Galeem's beams of light. She is soon vaporized by the beams upon reforming, and she and the other fighters (except for Kirby) are captured to be used to create puppet fighters for the non-fighter spirits.

Variants
Bat Within has a few variations used different characters that turn them into a different creature.

Moth Within
Moth Within is a technique used by Jeanne in both Bayonetta and Bayonetta 2, being one of her default abilities. Successfully using Moth Within is the only way Jeanne can activate Witch Time by herself without equipping accessories. The only difference from Bat Within is that the move morphs Jeanne into several white and red moths.

Hornet Within
Hornet Within is the variant of Bat Within used by Rosa in Bayonetta 2. The only difference is that Hornet Within gives Rosa the appearance of several oversized killer wasps.

Trivia

 * Bat Within is one of the four abilities that can transform Witches into animals, the other Bayonetta can change being Panther Within, Snake Within and Crow Within.
 * However, Bat Within is the only known technique that can transform witches into multiple entities.