The new Mortal Kombat X game will be released by NetherRealm Studios in 2015. The exact date is still uncertain and it would be best if fans were to await official announcements. One thing is for sure: the old roster from the original Mortal Kombat series won't be coming back, save for Sub-Zero, Scorpion, and maybe Raiden.
The game takes place 25 years after the Mortal Kombat reboot in 2011, also made by NetherRealm Studios. To bolster the tenth title in the series, the studio has introduced new fighters to replace the old ones.
First, the new characters. Cassie Cage is the daughter of fighters Johnny Cage and Sonya Blade. Nothing else is known about her past except that she possesses the styles of both her parents while also having a fighting style of her own.
Next is D'Vorah, a half-human, half-insect fighter. She uses insects with her attacks.
Another fighter is Kotal Kahn, the only known as the descendant of Shao Kahn.
Next is the fighter duo Ferra and Torr. The latter is an ogre-like character with his small companion Ferra riding around on his back. Their fighting style is more or less like a tag-team.
Scorpion and Sub-Zero are rival shinobi. In the original story Hanzo Hasashi, also known as Scorpion, was the deadliest shinobi in the Shin Ryu clan. His family and his whole clan, however, were killed by Lin Kuei and their assassin Sub-Zero. Scorpion swore to avenge his family and participated in the Mortal Kombat tournament where he killed Sub-Zero.
In the older sequels the original Sub-Zero, Bi-Han, was replaced by his brother Kuai Liang to avenge his death and joined in the next Mortal Kombat tournament. He was also later killed in the sequel and it is still unclear on how he had managed to be revived for Mortal Kombat X.
The last of the confirmed characters is Raiden, a thunder god in the Mortal Kombat universe and protector of the Earth realm. He is seen as a superhuman with supernatural powers such as the ability to teleport, flight, and control of lightning.