In Twisted Metal 3, the intro of the level London had Calypso talking about London and told the player to say hello to his "old friend." At first, I thought that Calypso knew about the British Royal Family because he said that right after he referred to the Buckingham Palace. Now I just realized, after almost 10 years, that Calypso was talking about Minion. As he is the boss that the player will face in London after defeating all the other oppositions. Counter Blitzkrieg
In Twisted Metal Black if you read Minion's coded messages you'd find that the entire game takes place in Sweet Tooth's head. With this in mind I suddenly realized that Darkside's ending makes a lot more sense. She was locked inside a mask and is fighting for the key, when she wins she must kill Mr. Creel, the man who locked her in the mask, if she wants the key. She does this then decides she doesn't want the key saying how great her mask is and then goes off to hunt for (and presumably kill) people like Mr. Creel. It seems stupid but consider Sweet tooth's fondness for his mask and his ending. He wants to remove a curse that causes his head to be on fire 24/7. Calypso gives him a cure but then says if he continues killing people it would wear off. He then rejects the offer within 10 seconds and kills Calypso. Put it this way they both decided to stay in their mask and hunt and kill people. What Darkside did is what Sweet tooth would've done.