Or is it 10Rat?
Stabwhisker the Odious
is functionally closer to The Rack than Shrieking Affliction, and I'm running three copies of him and 3 + 4 + 3, so... Regardless, this deck is an 8Rack variant. The discard suite is not quite as relentless as the traditional 8Rack archetype, but it is still enough to cripple most opponents.
One of the most fun aspects of this is deck is that while you are waiting for The Rack and/or Shrieking Affliction to deal lethal damage, you get to either play defense with tribal rats or you can even kill the opponent with the rats! A 5/5+ regenerative Pack Rat that is spawning token copies of itself every turn puts the opponent on a seriously fast clock.
The rats can put up one heck of a defense if you need them to. Just consider
Typhoid Rats
+ Swarmyard for a moment to get an idea of the possibilities. I decided to run the full playset of Swarmyard after seeing how effective this tends to be in practice.
Alternatively, you can beat the opponent to death with Pack Rat, Stabwhiskers, Mutavault, etc. Phyrexian Arena provides card advantage in a way that the 8Rack archetype never did, which provides fuel for Pack Rat copies and helps to makes up for the lower percentage of discard spells... as well as allowing you to create more rats, of course.
This deck is admittedly a little silly, but it's very fun and surprisingly effective.
+1's are appreciated!