Yeah, as a couple of people have already stated, MK: D wasn't a tournament. I don't really know how you got that idea, but it definitely wasn't a tournament.
The storylines for MK1 and MK2 both took place in tournaments. After that, there were constant battles and such against the forces of evil. In the MK3/UMK3/MKT storyline, the Earthrealm warriors are trying to defeat Shao Kahn and his forces. In the MK4/MKG storyline, the Earthrealm warriors are trying to defeat Shinnok and his forces. In MK: DA, the Earthrealm warriors are trying to defeat Shang Tsung and Quan Chi and their forces. Shang Tsung and Quan Chi held a tournament in Outworld for Li Mei to participate in. She thought by winning this tournament that she could free her people from enslavement. She won the tournament, but her people weren't freed and the Deadly Alliance tried to take her soul and place it in one of the bodies of the Dragon King's soldiers. Fortunately for her, Bo' Rai Cho came to the rescue and saved her.
There were quite a few endings and parts of some endings in MK: DA that occured in the storyline. The endings I'm referring to are as follows:
Scorpion's
Li Mei's
Mavado's
Frost's (the part where she takes Sub-Zero's Dragon Medallion and is killed by its immense power)
Reptile's
Cyrax's
Nitara's
Blaze's
Jax's
Hsu Hao's
You have to understand that the MK tournament was meant to protect the realms from being taken over. Shao Kahn and his forces were successful in many of the tournaments. Liu Kang defeated Shang Tsung in MK1. The tournament in Outworld was meant to lure the Earthrealm warriors into Outworld where they would meet their doom, especially if they even get to face off against Shao Kahn himself. The Outworld tournament was also meant as a diversion so Sindel can be resurrected. With Sindel at his side, Shao Kahn could use her to open up portals, namely to realms like Earthrealm so he can take the souls of people from there.