Why this deck? It's not easy to find good win ratio AND fun to play non repetitive decks. So that's the main reason, to have fun AND win.

-It's fun, consistent and not repetitive, you have very different games so you don't get bored.
-It is not expected, you have the advantage of confusing your opponent because it has cards from at least 3 different commonly used decks.
-Good starting / mid and end game
-Multiple win paths
-Not dependent on 1 or 2 cards to win
-very flexible deck

This deck is not like most used decks that requires no brain and just to follow the instructions to win or fail depending on what your opponent does, it's very flexible and you will have to use the cards to adapt your game to your opponent.

Some general ideas:

If you know the metha, it will be even easier to take advantage of the deck, if you go against slow decks, you can go for the shudder combo (if you dont kill it before with all the other stuff, and avoid Thrall, Deathseer) else go for Thrall, Deathseer and all kinds of boosts / evolves and leave Shudder as a strong move, but not the infinite combo.

-vs aggro, control (slow down) the table with taunts, Glacial Shard, removals, etc.
-vs slow decks, use your Murmuring Elemental + Far Sight / Zola the Gorgon / Saronite Chain Gang / Giggling Inventor. There's a lot of combinations you can do to populate the board, and then Unstable Evolution / Murmuring Elemental + Thrall, Deathseer / The Storm Bringer them. Or you can Electra Stormsurge + Bloodlust to get an insane +6 attack on each minion.

 Some tips:

Murmuring Elemental + Giggling Inventor gives you 5 annoying minions on the board + you can unstable evolution the main card to go to 6+ mana minions instead of the 2/1 5 mana minion. other good targets for [card]Unstable Evolution[/card] Corridor Creeper, Saronite Chain Gang, Lifedrinker

Shudderwock
It is not there as a stand alone win condition like the classic Shudderwock decks, it's just a good card to make good use of the battlecry of some cards. So dont play FOR it, play WITH it.

Thrall Deathseer
It's a very good card to combine with Murmuring Elemental or just alone to put pressure and also the power helps a lot in the mid game.

The Stormbringer
This card is to take advantage of the totems and how easy you repopulate the board, always try to use it in the correct moment, since a board clear could waste it.

Remember not to relay on one card, your win condition is based on fast populate + boost your minions, not in making the best Shudderwock combo, etc.

I'll update, I hope you enjoy it.

Some of the games:

vs Zoo Warlock Replay (nice defence)
vs Cube Warlock Replay
vs Mech Pala Replay
vs Zoo Warlock Replay
vs Odd Pala Replay
vs Big Mage Replay
vs Odd Rogue Replay
vs Quest Priest Replay
vs Odd Warrior Replay
vs DR Hunter Replay

 EDIT: As a smart player noted in the comments, facing fast agro decks like mage or rouge you could swap one card for Healing Rain that goes well with Electra 2x spell. I did a -1 The Strombringer +1 Healing Rain  and it's working fine! Stormbringer is too high cost at this point so... your choice.