With vigilance, a creature can attack and then block the next turn because it isn't tapped
There is a plethora of ways to create an infinite amount of tokens, causing infinite burn damage to win the game
Multicolor Inevitable Defeat Probably not good enough for three color, but interesting in the way Esper Pixie has shown with Hopeless Nightmare, where the ability to interact with an opponent while taking out chunks of their life can be something you can build around
Firestorm Market Price: $15.67 A one-mana burn spell extraordinaire, this card requires you to have a pretty stacked hand, but if you can pop off with a card like Enter the Infinite beforehand, you can immediately end the game
#21 I think I remmeber seeing you mention that in JC or something (occasionally read the posts, never really post myself)
Scavenger Regent is already a tough dragon to deal with, and its omen side can be a one-sided sweeper in many decks