This is the most recent iteration of the deck I've used to push to rank 40+ with level 2 and 3 cards.
Here's a quick summary of each cards purpose:
ManBearPig: The star of the show, this guy is the one you want in front tanking. The best way to play him is by placing him in the back followed by Angel Wendy / Mephisto / Ninjew
Mephisto: Fantastic support, he'll clear rats like it's nobodies business. Combined with Master Ninjew and MBP, it's almost a guaranteed health segment.
The Master Ninjew: Great for ranged support behind MBP as well as buffing your MBP, Angel Wendy, Mephisto. Gunslinger Kyle is a perfectly viable substitute.
Energy Staff: The ideal opening play. Energy staff allows you to smooth out your energy curve as well as stall so that you can do more fighting on your side of the field. This is important so that you can get a value advantage over your opponent and snowball.
Rogue Token: Perfect for cleaning up rats, gnomes, pidgeons and assasins. Great value play if timed correctly. Arrows with a body.
Shieldmaster Wendy: A well-timed shield from her can ensure that when your MBP pops a segment, she doesn't lose health from the blast wave. One of the best warriors currently in the game. Can be substitute for any other Warrior or Jimmy.
Dogpoo: Another beefy warrior, no skill but fantastic stats.
Hermes Kenny: Great assassin that gives increases mana rate, effectively reducing his cost to around 1 mana.
Choirboy Butters: Another valuable assassin that reduces his own cost when he dies.
Rat Swarm: Cheap units that can get immense value of timed correctly. Good for taking down tanks, other MBPs and assassins.
Zen Cartman: Best tank in the game, great for pulling aggro away from MBP and lumping units together for Mephisto synergy.