Tony wasn't the nicest person. To put it mildly. To be honest, he was a real crook that he didn't think about the others. He was an impudent man who cheated people out of money, then faked his own death and ran away with the loot. When he bumped into someone, he pretended to have amnesia and couldn't remember anything. And so on in a vicious circle. That's how Tony ended up in the "Tent of Dr. Parnassus" - an elderly man who was supposedly a visionary and if you go into his tent, you can find yourself in the world of your dreams. Shepard decided to stay and travel the world with the Parnassus troupe - his adopted daughter and the guy barker at the show - so he could remain inaccessible to his pursuers, and could also use his intelligence and charisma to trick Dr. Parnassus around his finger.