Let's make this clear. RAY is Zero from Mega Man X. There is no mystery about it. Like Zero, RAY fight in close range (With claws instead of a sword) and it's a powerful character in the Mighty No9 universe. With this DLC you have access to the Vermilion Detroyer Completing this stage (And thus beating RAY in a boss fight) will unlock the robot and make it playable in every stages of the game (With specific story and cutscenes). However there is something special about RAY. Your life bar will always go diminish. All the time. You must kill the enemies one after the other to recover your health, giving the game the flavor of a time attack mode. It's very cool and fun. It's just a shame that such content is being locked behind a DLC.