Though it fared well against Volfogg and initially matched GaoGaiGar in capabilities, EI-15 was beaten by the true Hell and Heaven - according to Kousuke Entouji, because an imposter never has that which makes the original, the hero's proof. The strain of using Hell and Heaven against EI-15 took its toll, however, in that Cyborg Guy was left nearly comatose from the strain on his cybernetic parts.