The Rainbow Barrier is one of Annie Hamilton's special techniques, having only appeared in one game. Basically, Annie would sweep her arm downward through the air, leaving behind a rainbow-like trail of energy in its wake. It can provide defense against incoming attacks, on both the ground and in the air. This special move was only featured in the first Power Instinct. It's possible, however, that she changed it up to create the Rainbow Rise technique in its place, which proved to be an effective trade off.