Hearthpwn

Person above beat me to it by a few minutes but here is my take on the Wisp combo.  I thought Charge was more of a Warrior thing.

Combo: Wisps of the Old Gods (6) + Savage Roar (2) + Power of the Wild (1) + Detonate! (1).  Requires hits on all 4 from Emperor Thaurissan.

28 Damage from Wisps + Hero Attack for 2 Damage = 30 Damage.  I know this will not work if the enemy has any minions on the board but it is "capable" of dealing 30 damage to the enemy hero and is more balanced this way.

Warrior OTK!

Emperor Thaurissan

+ Uroe, Harbinger of Terror

+ Captain Greenskin

+ Bloodsail Cultist

+ Bloodsail Cultist 

+ Upgrade

+ Upgrade

32 DMG One turn kill. If the enemy have Taunt you may use Southsea Deckhand + Excecute to come over them.

Besides, this weapon may be also useful in some Warrior Pirate Decks, fyi, quite flexible.

Flavor text: "I sp-sp-spell YOUR DOOM!" (look up Yogg-sarons' if you don't get it)

Because OTK comboes can be unhealthy for the game, They best way to balance them is with telegraphed setups or difficult requirements.

By having to discover the copies of a card you want, it becomes slightly more challenging, because most combo decks hoard cards. However, even if you have more than four cards in your hand when you play this (this plus three others) you still have a reasonable chance to draw the card that you want, or you could improvise and choose another possible option. It is also much easier to discover the card you want the second time, because you will have 3 copies at least. Or just use it on some big minion if you dislike comboes...

(Additionally, the stat line might motivate people to try something akin to a divine spirit inner fire combo.)

You can make a lot of different Otk comboes with this, even without Emperor

Example:

Play Stuttering spellmage -> discover sinister strike -> repeat -> play evolved kobold (4) - > spam 6 sinister strikes (1)(1)(1)(1)(1)(1)

Epic Questing Adventurer + Charge + Inner Rage ×2 + Stonetusk Boar ×2  +Murloc Tinyfin

http://imgur.com/a/lu9Qy

Brave Apprentice OTK

In your hand have:Malygos, 2 Kobold Geomancer, 2 Arcane Blast, 2 Brave Apprentice. Get an Emperor Thaurissan tick on each card. Next turn, play Malygos for 8, both Kobold Geomancers for 1 each, both Brave Apprentices for 0 each, then Arcane Blast each, dealing 32 damage face. 10-mana OTK in seven cards (plus Thaurissan).

My goal was to make a card that would be strong on it's own, but also enable a fun OTK with existing cards. I think  Brave Apprentice is an all-around good card that could be used in Tempo Mage or even a more control Mage.

(Sorry it uploaded as an attachment.)

Flavor: just finding an ability name from wow, so i google 'shadow priests' and i got this

So, the cards you need is Prophet Velen with 3 Mind Blast, or really just 6 mind blasts.

Without velen, 6 mind blasts will do the job, but with velen, there cant be any 2 mana mind blasts ( 7+2+1+1=11>10) so you should have played void eruption before drawing any of the 2 2 mana normal mind blasts that you put in your deck in the first place, or just use emperor to discount velen himself.

Seems really great value with the 1 mana cycle alone (*looks at Purify and says "right Brode?") but it adds inconsistency in your deck, especially if you have 2 of these, the first two mindblasts will be dead draws against most other decks because you're probably not the aggressor in the matchup.

Thaurissen tick on everything
Totemic Wrath -> Malygos -> Lightning Bolt -> Lightning Bolt for 32 Damage.

After reducing the cost of your cards with Emperor Thaurissan:

N'Zoth's First Mate, 2 Bloodsail Cultist, 2 Upgrade!, Vaneesa VanCleef.

Vanessa VanCleef deals 5 * 7 = 35 damage to the enemy hero.

This card is more of a "leading to lethal combo" than making the plays itself.

Basically with this card, you can create yourself another copy of ice lance (freezemage), cold blood (miracle) and other potential lethal cards.

It's more of a spell than a minion, but because there are no legendary (two of them would not be balanced) or all-class spells I made it a minion with a small body like thalnos.

Putting a copy into your hand is like a card draw, and because you can choose which card, i gave it a +2.5 mana considering its unique abilities.

I was considering making it into a 1/1 taunt, so combo decks can survive against aggro, but for that, the card cost would have to be higher which makes the card too costy for combo decks.

You can play this before your lethal turn, or during your lethal turn (comboes well with cold blood), or you can copy an irrelevant minion or spell to survive until your lethal combo.

I know almost none to nothing about the WoW lore, but did a quick read and found out that the titans used the pillars of creation to shape the world (if i read correctly, many dont believe this and say it was the god who made the world)

The image is an ACTUAL picture of the so-called "pillars of creation" in out universe... but im sure there are better images/name to use.

EDIT: Fixed some typos on the card and on the description.

Here is my Idea for this week competition,

First you hit this 6 card with Emperor Thaurissan : Pursuer's Blade, Southsea Deckhand, two Tinker's Sharpsword Oil, Deadly Poison, and Eviscerate. The total mana cost of all card after Emperor Thaurissan discount is 10.

The combo is you equip Pursuer's Blade, summon Southsea Deckhand then cast two Tinker's Sharpsword Oil and Deadly Poison. At this point you have 10 attack weapon and 8 attack minion with charge. You Attack with Southsea Deckhand to deal 8 damage than you hit the opponent's face to deal 10 damage and with Pursuer's Blade deathrattle you will deal another 10 damage. You now deal 28 damage and you can finish it off with Eviscerate to the the opponent's face to deal total 32 damage. 

I hope you like my card!

Doom Lord Kazzak has everything you would ever want for warlock. He has high stats at 9/9 and he gives all of your other minions Charge enabling OTKs and massive damage. There is only one problem; Doom Lord Kazzak is 11 mana. Since he is so expensive you have to cheat him out. There are numerous ways to do so; with his Demon tag you can summon him off of Void Caller, you can cheat him out with alarm-o-bot, or lower his mana cost with Emperor, or probably the easiest most unfair way simply summon him out by discarding him through soul fire or any other means. While this gives you a huge advantage with a turn one soul fire into him your opponent still has a few turns to respond to him because he does not give himself charge. 

OTK combo 1 of infinity: Takes 10 mana

-Summon 2 Darkshire Councilman
-Summon 2 Abusive Sergeants 
-Soulfire *4 Damage
(Discard/Summon Doom Lord Kazzak)
-Soulfire *4 Damage
(Summon your last card Silverware Golem)

You will have one 10 attack Councilman, one 5 attack Concilman, two 2 attack Abusive Sergeants, one 3 attack Silverware Golem. Plus the 8 damage from two Soul Fires means you are doing a whooping 30 Damage. Ta-da Lethal :D 

This card can be used like a win condition in the Yogg and Load decks, by reducing the cost of this card and Unleash the Hounds 

with Emperor Thaurissan you can deal a lot of damage by playing several cheap spells to boost the damage of your hounds.

Other than hoping you survive one turn to do 30 damage the following turn, I see two ways to win on the spot with this card.

1. In warrior with Charge. This requires both cards to be discounted by Emperor Thaurissan, and misses out on the rules of only one turn of Emperor Thaurissan, because this combo is 11 mana, so I know this one falls short for the specific rules of this contest.

2. The opponent does not have enough cards left in their deck to draw until they have 9 in their hand, so it keeps drawing and drawing and drawing... because they never reach those 9 cards in hand. Fatigue kill. I think this one is a bit more stylish, and I think it's within the rules of the challenge?

(In case image fails)
Warlock Minion "Void Abomination"
9 mana, 8/3 Demon

Charge. Battlecry: Destroy adjacent minions, gain their attack and health.

(To be clear, it's the exact same effect on Void Terror)

OTK Combo (assuming Thur discount):
1) Wolfrider + 2 Power Overwhelming (2 mana discounted)
2) Attack
3) Play Void Abomination (8 mana discounted)
4) Face is the place
5) Perfect 30 hp one turn combo, at turn 10

Edit: Changed from 8-mana to 9-mana for balance purposes, as well as fixing a capitalization typo or two.