UR Burn is one of the top decks in the format and can be built in many different configurations. The foundation of the deck usually consists of 4 Serendib Efreet, 4 Lightning Bolt, 4 Chain Lightning and a couple up Psionic Blasts.
The rest of the deck can either be built to maximize the aggressive side with more burn, Electric Eels and/or Flying Men, or it could be built more as a tempo deck by adding counterspells and some control elements. You can also build the deck with some amount of main deck Blood Moons and Energy Fluxes if you want to be a little hateful.