One∞Two∞Three! Brilliant Activation!

(One∞Two∞Three！ ブリリアントアクティベー！) is the main transformation phrase that the cures in 1-2-3! Brilliante Pretty Cure use to transform into their respective Pretty Cure alter egos.

Miho to Cure Midnight
First, Miho taps her Brilliant Brace three times as she shouts One∞Two∞Three! and as light pours out of the brace, surrounding Miho's body excluding the head, she then shouts Brilliant Activation and the light surrounding her body turns into a light blue robe. She then does 5 pirouettes in a row and her skirt is formed. She then taps her chest three times and the final part of the robe turns into the top. Several specs of light then spew out of the Brace forming her bow. Finally, she strokes her hair and it shifts from brown to a lighter brown as well as it growing longer and tying itself into twintails. She then claps three times and recites her introduction speech while doing her final pose.

Shiro to Cure Dove
First, Shiro taps her Brilliant Brace three times as she shouts One∞Two∞Three! and as light pours out of the brace, surrounding Shiro's body excluding the head, she then shouts Brilliant Activation and the light surrounding her body turns into a white robe. She then jumps into the air and her dress is formed. She then taps her arms, causing her arm warmers and boots to appear. Finally, she strokes her hair and it shifts from dark brown to blonde as well as growing longer and braiding itself. She then claps three times and recites her introduction speech while doing her final pose.