Read it again and the again. Then you might see that it says he sacrifised HIS POWERS. He was confirmed at E3.

Raiden is a mortal now...is what the bio means. Yes, Raiden is alive, but he has no powers now. And cmon, we ALL know that the dragon king isnt that strong! Raidens blast would have surely killed the Dragon King, unless the dragon king is made of rubber, like baraka.

I first thought that Raiden had sacrificed his whole being to destroy the Dragon King. That was not the case, I thought wrong.

Raiden hoped that by sacrificing his essence of power he would destroy the Dragon King. The blast that he created did not kill the Dragon King and Raiden was no longer a god.

Raiden is now a mortal just like the warriors he had guided in the past. Raiden could now die at the hands of mortal warriors. I think this change in the story leaves the fans to wonder what will happen to Earthrealm if there are no gods protecting it?

Oh i get it now he just sacrificed his powers oh i thought he sacrificed his whole self my bad

I thought he was dead, too, but upon review, it is clear that he is coming back.

I'm guessing that Kitana is going to replace Jade in the prison, based upon the IGN info, too. Jade is almost guaranteed to in the game based upon Sindel's bio.