Outworld is a realm, ruled at first by the dragon king onaga though despotism, however before onaga could reach imortality, he was poised by his adviser shao kahn, who later took the thrown and became the second ruler of outworld. Both Khan and onaga wanted to expand the realm, usually by force. (which is described in the first three games of mortal kombat).
Outworld is a very large realm that has multiple different landscapes, However The primary landscapes appears to be a huge, purple wastelands, dense forest with animated face (they can even eat a person if they would come to close to the trees), desert, pools of acid,and enormousness mountain tops.Similar to the realm Edenia, the realm outworld is full of magic. And as for the citizens, the poor oppressed souls live in scatted villages.