I was thinking, if evil does prevail in MKA i think a great story for MK8 would be a uprising.
Evil is in charge of all the realms (Maybe a powerful sourcerer) nearly all of former MK Characters are gone, some known as legends. The is a stir in the Earthrealm, whispers of rebellion spread across the relams. The new race (like the tarkatans were) are loyal to the Evil and battle the rebels.
I was thinking of names.
MK New Hope.
MK Dawn of a new sun.
MK Uprising.
Mk Rebellion.