After Starcsream was exiled from the nemesis,he was able to get some of his stuff,one included a mask. After all,he was used too surviving on his own he wasn't useless as others really think. he observed the autobots,hiding of course,he wore the mask as he was more comftarble others not knowing who he is. he got bored after a while and started to make himself a little bit knowed. (Kudos to whoever made the art,i just changed and added some things,i also don't own transformers,pretty obvious)