I recently opened Hir'eek, the Bat and was messing around with different ways to make a handbuff warlock viable when I realized that Spirit of the Bat and Usher of Souls both trigger off minions dying, so logically, the next thing to do was to make a Hir'eek, the Bat and C'Thun Warlock Deck.

To maximize the amount of minions we can have dying, a lot of the cards in the deck just generate 1/1s for trading off to trigger Spirit of the Bat and Usher of Souls.  Since the board will be filled with tokens a lot, I'm also trying out Demonbolt.  I'm also using a few cards that destroy our own minions EVIL Genius and a single copy of Ratcatcher since its pretty good with handbuffs and can preserve the stats from Power Overwhelming.

I've also included Darkshire Councilman as another way to abuse all of the token summoning this deck does.  He can get a lot of damage in if left unchecked.

The main gameplan is usually to just try to get all the buffs to land on C'Thun, but Hir'eek, the Bat can get pretty big too or just be used as fodder for Spirit of the Bat and Usher of Souls.  (8 mana Rafaam's Scheme Wooo!)

Other Considerations:

Grim Rally would be good with all the tokens in the deck, activates minion death triggers and could be used with Hir'eek, the Bat to sacrifice one Bat to give the rest a stat boost.  I'm just not really sure about where to fit it in.

Knife Juggler also works really well with all the token summoning like a 3rd and 4th copy of Darkshire Councilman.

Blood Troll Sapper may be worth trying out since it can convert all the minion killing this deck likes to do into SMOrc damage!

Soul Infusion and Arena Fanatic could help with getting big Hir'eek, the Bats, but that's not really the route I wanted to go with the deck.

Possessed Villager can be used in place of Mecharoo for premium voicelines and to play around the ever-present E.M.P. Operative! Just watch out for Dyn-o-matic.