It wasn’t too long ago that we heard Skarlet — a blade-wielding hottie — would be joining the Mortal Kombat cast, but now we know when she’s coming and who will be coming after her. The new trailer below says “download now,” but the Skarlet downloadable content will really hit the Xbox 360 and PlayStation 3 on June 21, 2011. The trailer goes on to tease three additional characters — Kenshi, Rain and a fighter to be named later…