well im not agreeing with anyone but i do know graphic artist do take an existing pic,or what ever they are using and add fonts,add additional pics etc,
i know this since my wifes graphic artist for there company does this,as well as some from my company i work for they do this,they can purchase pics via other web sites or other artists and modify them etc,
so in a sense he is correct he never claimed to be the artist of the devil,he took an existing piece and added or deleted what ever needed to be done, thats what alot of graphic artists do. so hes not doing anything that alot if not most graphic artists do now days,
now if he wanted to use the pic he would have to get the rights to use it in a production job.
just my 2 cents from i have seen from graphic artist i have come across