Raiden - I know the name Raiden comes from the Japanese thunder god, but I decided to use the Chinese thunder god, Lei Gong, for inspiration. Because of Mortal Kombat having a lot do with the Shaolin monks of China, I went with Chinese mythology. Lei Gong is described as having blue-green skin, claws, birds wings, a beak, and carries a hammer and drum. Now, I kept him human looking but liked the idea of the blue-green skin. The clothing was inspired by an image I found of the god, plus other Chinese styles. I did my best to mix the two ideas so that it would still resemble what most know Raiden to look like, while also being an original, interesting take on the character.
Liu Kang - For this design I pretty much just went with the classic Shaolin monk look for him. I kept his more typical red and black color scheme though to keep him somewhat recognizable.
Sonya Blade - Considering Sonya Blade is supposed to be a member of a Special Forces unit, I wanted to move her away from the spandex and leather and into something more military looking. I understand that she is only wearing an underarmour sports bra here, but this would only be while participating in a tournament match. I plan on working up an image of her in all her SF gear later on.
Johnny Cage - I went with the idea that he's a UFC fighter-turned-actor and is participating in the tournament to prove that he still has what it takes. So, I went with a UFC look using the typical black, red and blue color scheme he's often seen wearing.