Well ok raidens bio Raiden sacrificed himself by releasing his god like essence(btw told u he was alive). It created a ethreal blast and didn't harm the DK.

Theory one:
Raiden lied on the ground weak and hurt from the blast. The blast burned his clothes. The blast caused his eyes to be red( this theory mainly by DMitch)

Theory two:
Raiden unleashed his blast and some of the DK's evil went into his body. He was stunned for awhile when he awoke he noticed that he has changed. His Powers had become more powerful and darker causing his features to change. He was now part evil and good.

now I have two branches from this

He could control his powers to keep him good to decieve the DK. When he had the right chance he would challenge him to Mortal Kombat.

Or he has now turned evil on the side of the DK and is a big threat to everyone.(My theory)

SO what do you think if anyone else has theories please list them with your thoughts.