"They were with Shao Khan's army when he invaded to try and merge Earthrealm with Outworld," Cassie says.

"Up until then he'd been following the Elder Gods' rules. You're only supposed to be able to merge realms after you defeat its champions ten times in a row in a secret once-in-a-generation tournament called Mortal Kombat. But once he brought his armies to Earthrealm, it all stopped being a secret anymore."