Cloaken Dagger occasionally spreads chaotic transformations through ponykind in Eris's name, and Dzamie is, well, Eris's most favored follower. They both abhor the boredom of predictability, and so they and Eris find themselves attracted to each other. As for the Dzamie/Cloak part? The katul and changeling whose magic literally works off of their pride/self-image would absolutely fuck themselves when given the opportunity.