According to the e-Hobby story, this is Optimus Prime not Nemesis Prime or Scourge.
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.e-hobby.co.jp/&prev=/search%3Fq%3De-hobby%26hl%3Den%26lr%3D
e-Hobby Story translated into Japanese English.
The twin Missile Launchers that had been created for DECEPTICONS. Though those are usually proud of high accuracy, they are necessary to take in a solar light to increase the power. By giving black coating to OPTIMUS's body, the Missile Launchers absorb a solar light efficiently. And those Launchers are possible to shoot long range missiles which increased the further power. However, when a battle in the coating state attains to a long time, OPTIMUS himself may cause overheat so that he probably has to end a battle for a short time.
