I've recently fallen in love with the idea of a deck designed around Kiln Fiends, and Scars of Mirrodin has only made it better.
As you may know, the Kiln Fiend gets +3/+0 every time you cast an instant or sorcery. Which is good on its own, but hey, it gets even better: What if you made it unblockable? You could smash the enemy in the face for quite a bit of damage. But hey, let's make it even better. Let's give the Kiln Fiend Double Strike. Double the damage, double the fun! Now, we could make it even more absurd: let's make the Kiln Fiend deal poison counters. Now, you're probably saying, "that's excessive and absurd," and you'd be right, but man do I bet it's fun to pull off.
So, how do we do it? It's important to stay Standard Type II Legal, for ease of access to cards.
For starters: Kiln Fiends. 4 of them. They're the meat of the deck's awesomeness.
Unblokable comes from Distortion Strike (and an additional +1, and Rebound in case you... uh... miss?).
Double Strike comes from Assault Strobe, a new single-red sorcery in Scars.
Infect (for poison counters) is from Tainted Strike a single-black sorcery from Scars, and also gives +1/+0.
Now, what does that put us at? Kiln Fiend has a base 1/2. +1/+0 from Distortion Strike, +1/+0 from Tainted Strike, and +9/+0 for casting three instants/sorceries. Grand total: 12/2 Unblockable Infector with Double Strike. That means 24 poison counters. Given it takes 10 to kill, you're operating at incredible efficiency. You don't even really need the Double Strike; just any instant or sorcery, but I like Assault Strobe.
And yes, this does create a hilarious turn three win. If your opening hand is a Swamp, a Mountain, an Island, Kiln Fiend, Tainted Strike, Distortion Strike, and Assault Strobe, you should definitely not Mulligan.
Now, I know that there's the chance of removal, and the deck suffers in late-game, but given it's a UBR semi-control aggro deck, you should tend to be okay. Of course, if the enemy isn't dead by, like, turn seven, it's often time to just give up. I personally love the deck idea, especially if supplemented by Leyline of Anticipation, Surreal Memoir, and Mnemonic Wall. Surrokar Spellblades can also be rather hilarious for later game, but beware decking yourself. That's generally bad.
Comments greatly appreciated; after Scars' official release, I intend to build this for trying my luck at the quick-kill. Hope others like it too.
~ The Planeswalker
PS - My girlfriend says Kiln Fiend looks like a kitty, and that with Lightning Greaves it's Puss in Boots.
She's cute like that.