If Imperial Painter deck were a little bit better, it would be bad news for the blue mages out there, myself included. No one wants to play against a deck with anywhere from four to eight Red Elemental Blast effects, and thanks to Painter's Servant this is the only deck in the format that can maindeck them.
In the last couple years, we've seen the white splash for Enlightened Tutor rise in popularity. While the tutors are card disadvantage, that doesn't matter too much if you're using it to assemble a lethal combo: ultimately the consistency matters far more than losing out on a card. Being able to find things like Trinisphere and Circle of Protection: Red in the sideboard games matters quite a bit.
This deck isn't simply a Painter deck though. Perhaps in an effort to be more threat-dense, Matsole added the Bomberman combo to the decks which uses Auriok Salvagers plus Lion's Eye Diamond to make infinite mana. Once you're there, you can use Pyrite Spellbomb or Sunbeam Spellbomb to draw your deck. This combo also gets around your opponent having something like Emrakul, the Aeons Torn in their deck, which would effectively negate your first combo.
The deck already wants to play some number of Lion's Eye Diamonds. You're often able to sneak a Painter's Servant onto the battlefield alongside a Grindstone, but it's unlikely that you have three spare mana lying around. Lion's Eye Diamond goes a long way toward throwing off your opponent's math, allowing you to win out of nowhere.
I'll always have a soft spot in my heart for a deck playing two combos, and even though this deck doesn't have Brainstorm I love it all the same.