Hearthpwn

Diablo Reasoning: 

Xul, Cryptic Necromamcer: Xul's passive Raise Skeleton, makes it so whenever an enemy minion dies around you they are raised back as skeletal warrior that fights for you. Xul's ability does exactly that, summoning skeletons whenever an enemy minion dies.

Valla, Demon Hunter: Valla's ability depicts her Hungering Arrow ability, an arrow that homes onto enemies and goes through them, then seeking out a new target, or hitting the same one if no other targets are around. Her ability essentially has her shoot an "arrow" that will home onto 4 enemy minions and deal damage to them.

Li-Ming, Rebellious Wizard: Li-Ming has an ability called Magic Missiles , It's really just a renamed Arcane Missiles and is a Diabloian Wizards Arcane Missiles. Li-Ming will periodically give you Arcane Missiles to use whenever they are off "cooldown".

Tyrael, Archangel of Justice: His ability is quite powerful and it mimics the effects of his Sanctification ability which makes all allies in the field of light invulnerable for a few moments. 

Azmodan, Lord of Sin: Based on his General of Hell ability, which buffs all minions in its radius. I changed it so that it affects demons only.

Leoric, The Skeleton King: Drain Hope is the ability I used here which sucks some enemy's health and restores you with 25% of damage dealt. I just changed that percentage to 100% as that would be quite awkward in Hearthstone.

Kharazim, Veradani Monk: Based on Divine Palm which protects an ally from death for a turn, is what I used for his ability in Hearthstone. Redemption's effect was the best way to translate this.

The Butcher: Based on the Fresh Meat passive which increases his attack whenever he picks up Fresh Meat from dead enemies.

Auriel, Archangel of Hope: Based on her Resurrect heroic, it's based on the card Resurrect. The difference is that it's only for this turn that is meant to reflect heroes eventually are revived after the death timer ends.

Nazeebo, Witch Doctor: Nazeebo's ability is intended to mimic the Corpse Spiders ability. This allows Nazeebo to throw out a jar, that releases spiders if it hits an enemy. One the spiders are released, they will mercilessly follow the enemy and attack them. Gothik's spectral mechanic from Naxx worked well for this.  

Cassia, Warmatron: Cassia's trait, Avoidance, reduces basic attack damage to her while moving. For her card I made it so her trait activates when attacking. I also threw in Windfury for the effect of her Fend ability, which allows her to perform multiple attacks in a quick succession. 

Diablo, Lord of Terror: Diablo's trait, Black Soulstone makes it so once he's collected enough souls, he can resurrects in 5 seconds. The Lord of Terror can never truly die, but you get a peaceful period of one turn without him to do some terrorizing. 

Starcraft Reasoning: 

Abathur, Evolution Master: Not much to say here. He really is just an upgraded Master of Evolution.

Kerrigan, Queen of Blades: I choose to use Kerrigan's Ravage ability, which deals damage, then if it kills goes off cooldown. Her Hearthstone cards does this letting you deal 6 damage in total divided between 2 minions if planned correctly.

Hierarch Artanis: For Artanis when he comes in he will use his Suppression Pulse, dealing a small amount of damage and "blinding" your opponent's minions for a turn, stopping them from attacking for a turn. 

Sergeant Hammer: Based on her Napalm Strike ability, which sends out a rocket to blast an area for damage and leaving a small AoE field that deals damage to those that step in it for a bit. Thus her ability does not affect just one minion but an AoE field will be left to damage the ones next to it. It also has a fairly short cooldown.

Nova, Dominion Ghost: Like Abathur this was more so inspired by her profession. Yet for her ability I took an old ability from the WoW TCG called Long-Range which prevented damage to the minion when it attacked another minion.

Zeratul, Dark Prelate: Void Prison. The strongest heroic in Hots. What it does is put enemies allies who walk into it into stasis. stasis is an effect that makes them immune to damage, but unable to move or attack. His effect mimics its effect, only on enemies.

Jim Raynor: Raynor will call down the Hyperion to shoot at your enemies just like his ultimate, Call Hyperion. It's a good board clear slapped right onto a body.

Dehaka, Primal Pack Leader:His effect was based on the Isolation ability, which dealt damage and Silenced an enemy and slowed them. His Hearthstone ability is basically the same effect, minus the slow.

Alarak, Tal'darm Highlord: Based on the Deadly Charge heroic, Alarak basically charges in ignoring all who stand in his way.

Tassadar: Tass's Force Shield defines him. This allows Tass to shield an ally until your next turn, then they lose that bonus health. 

Warcraft Reasoning: 

Murky: Murky will use his March of the Murlocs heroic to flood the board with Murloc Tinyfins. Similar to a Onyxia, except for both players.

Chromie, Keeper of Time: Based on her Temporal Loop ability, like it she will send a minion back to it's "position" it was a moment ago. A small bonus is if they are actually your card and they get hit they go back to your hand, not your opponents. 

Tyrande Whisperwind: An ability that mimics Tyrande's ability Sentinel ability, that deals damage to a enemy and reveals them on the map for little while. For this card I had it so they lose Stealth to mimic being revealed.

Genn Greymane: His ability combines Inner Beast which increases attack speed and Full Swipe which damage enemies in a wide radius in front of you when used. 

Brightwing: My favorite card that I've created so far, Brightwing has the Polymorph ability which does the exact same thing as Polymorph in WoW and Hearthstone. So I threw in some awesome Dragon synergy and made it so that Brightwing will Polymorph an enemy if you got a dragon friend around, we all know how much Brightwing loves "friendship". (Brightwing is actually a maniac, do not trust her.)

Li Li Stormstout: My favorite and most used hero needed an unique ability. So for Li Li's effect she will use Jug of a 1,000 Cups which is an AoE heal that randomly heals people based on their how low or high their health is, this will let you do a fraction of 1,000 cups for every friendly minion you have out who has taken damage.

Lunara: Lunara's basic attacks inflict the poisoned condition on enemies. So I took a certain someone's toxins to apply this to Hearthstone.

Medivh, Last Guardian: Poly Bomb is Medivh's strongest Heroic. This allows him to transform an enemy into a sheep and if an enemy is by them at the end of the duration, they will also be transformed into a sheep. Then the cycle continues.

Jaina Proudmoore: She summons a Water Elemental in Hots and chills enemies, not much thought put into this one.

Chen Stormstout: A defensive card, who's Fortifying Brew ability allows Chen in Hots to gain a shield while he's drinking. I also added in the functionality of the Enough to Share talent, which allows Chen to give an shield to nearby allies while drinking his brew. 

Valeera Sanguniar: Valeera has some difficult to translate heroics, so I used her stealth ability Garrote. Garrote throws a DoT on the target and silences them for a few seconds. Thus she silences any enemy she attacks for a turn.

Blademaster Samuro: The Blademaster can use mirror image to create multiple versions of himself, though the images have less health. His design is similar to the original idea for a Jandice Barov.  

Gul'Dan, Dark One: Gul'Dan's main source of damage in-game is the Corruption ability. I thought for a long while how I could put his affliction theme in Hearthstone and decided why not give him the Corruption effect from Hearthstone! 

Overwatch Reasoning: 

Zarya, Defender of Russia: Zarya's trait allows her to gain energy when she takes damage while her Shield abilities are up. The more energy Zarya has, the more damage she does, so I took that and applied it to a Divine Shield.

Tracer: Tracer can manipulate time, her card though not too original represents that.

Lucio, Freedom Fighter: Lucio's Sound Barrier Heroic allows him to shield allies for a short time. For his card I took this and made it a mass health boost that lasts one turn, letting you trade effectively. 

Genji, the Sparrow: Genji's effect is based on his swift strike ability that let's him dash in and deal damage. If it kills the target or they die in 1.5 seconds, it's reset. So for the second attack he hits the enemy hero if he kills the minion.

• 7/12/16 - Created. Added Li-Ming, Tyrande Whisperwind, Kerrigan and Hierarch Artanis. Rework on Tyrande.
• 7/13/16 - Added Tyrael, Sergeant Hammer and Genn Greymane.
• 7/14/16 - Added Azmodan, Zeratul, Li Li and Genreal of Hell. Created Tokens section.
• 7/16/16 - Added Brightwing, Leoric and Nova.
• 7/18/16 - Added Medivh, Dehaka and Kharazim.
• 7/19/16 - Added Lunara, The Butcher and Jim Raynor.
• 1/28/17 - Added Alarak, Jaina and Auriel.
• 1/29/17 - Rework on Medivh and Nova.
• 1/30/17 - Rework on Zeratul.
• 2/1/17 - Added Chen and did a rework on Dehaka.
• 2/4/17 - Created Overwatch Section. Added Zarya, Tracer and Lucio.
• 2/7/17 - Added Nazeebo and did a rework on Tyrael and Chromie. Updated art on Li Li and Tyrael. Organization on O. Added Changelog (What you're now reading).
• 2/8/17 - Added Tassadar and did a rework on Tracer and the Azmodan's General of Hell token. Updated art for Tracer and Azmodan's General of Hell token.
• 3/4/17 - Added Valeera Saguniar.
• 4/1/17 - Added Cassia, Warmatron and Blademaster Samuro.
• 4/4/17 - Added Diablo, Lord of Terror and made changes to Hammer and Samuro.
• 4/25/17 - Added Genji, the Sparrow . 
• 5/10/17 - Added Gul'Dan, Dark One