User blog comment:J1coupe/Watch Dogs vs. Sleeping Dogs. Epic Rap Battles of Video Games Season 6./@comment-24328089-20140828042254/@comment-5264252-20140828042511

He already did a Battlefield vs Call of Duty battle. http://epicrapbattlesofhistory.wikia.com/wiki/User_blog:J1coupe/Call_of_Duty_vs._Battlefield._Epic_Rap_Battles_of_Video_Games_Season_4.