So what does he do? He sends his champions to kill the warriors.
The souls of the warriors who Raiden (who, by the way, is a rebel frowned upon by the gods) chose to stand against Kahn's rule. Uh-oh! The Elder gods can only watch as Kahn steals the soul of every human being and merges Earth with the Outworld. So he revives his ten thousand-year-old plan of resurrecting his queen Sindel, but not on Outworld, on Earth. Shao Kahn was a sore loser after suffering defeat in MKII. The game revolves around the story of MK3. Mortal Kombat Trilogy basically takes these four games and merges them into one big game, creating as Jim Ross of the WWE would say: 'One good ol' fashioned slobberknocker' of a game.
Which brings us to Mortal Kombat Trilogy.