Insta-Shield

Better known to laymen as the Insta-Shield, the W Kaiten Attack first debuted in Sonic the Hedgehog 3.

Jump, then tap the A button again while in midair to perform a quick 360° slash that briefly expands Sonic's attack radius and renders him temporarily invincible.

http://www.captainwilliams.co.uk/sonic/sonic16bit/sonic3/images/instra.png

W Kaiten Effects

• Performing a W Kaiten with a fire shield causes Sonic to briefly turn into a fireball and fly across the screen at high speed.
• Performing a W Kaiten with a water shield makes Sonic bounce in his bubble.
• Performing a W Kaiten with a lightning shield makes Sonic jump twice, with sparks flying off of the shield.
• Performing a W Kaiten while being Super Sonic does nothing.
• Performing a W Kaiten while being Hyper Sonic causes all badniks on screen to be destroyed. Sonic is also propelled in much the same way as if he did the W Kaiten with a fire shield, but the player can control the direction of his flight with the D-pad.