Hearthpwn

Slow card, but fun. I got Kazakus potion to deal 25 damage  :) 

10-cost

Getting a fireball of 10 damage and an arcane missile of 8 with his is so satisfying!

This got my Fireball doing 9 damage at one point...it can get pretty crazy if you remember to use your hero power before casting anything! ;)

 Knowledge is power - and he knows a little.

What a shame. There's so much design space for cards with spell damage but a vast majority of spell damage cards will never see play in constructed. For those few decks that need spell damage, there are three or four cards which are simply the best. If you need spell damage, you don't need much, and these few particular cards will always suffice.

1. Bloodmage Thalnos. If you can't take advantage of his spell damage, he'll cycle for 2 mana. Moderately conditional cards that cycle for 2 mana are plenty playable (see Flare). If you can take advantage of his spell damage, he's often like a 2-mana Fan of Knives plus the 1/1 body.
2. Azure Drake. You take a Ogre Magi, increase the cost by 1, and append "draw a card." Appending "draw a card" usually costs more than 1 mana on a card; cards that cost 1 more mana and have "draw a card" tend to be very strong (like Fan of Knives or the 1-mana cycling 1 damage that used to exist in beta). Because of this, the Drake tends to be significantly more powerful than other Spell Damage cards when you want both a relevant body and spell damage.
3.  Velen's Chosen. Giving a minion +2/+4 in Priest for 3 is already super powerful and Priest decks would still run the card if it did not give Spell Damage. By the nature of Priest, allowing Priest minions to trade and survive is very dangerous as they will use healing to undo the damage, then draw cards with Northshire Cleric. And then it also has Spell Damage for use with Holy Nova and the like... ugh.
4. Malygos. If you want to include a Spell Damage minion for use in lethal combos you include this guy. This guy deals 5 damage to the enemy hero every time you hurt the enemy hero with a spell, so if you can use Emperor Thaurissan or Ancestor's Call (or Aviana kappa) to get him out for cheap, then play multiple cheap damaging spells, you can easily reduce the enemy from 20 health to nothing. 

I learn.

I actually really like this guy in Arena. Sure, I wouldn't take it over Chillwind Yeti, but it's surprisingly strong. Most people tend to not prioritize it as a massive threat because they think "Spell damage? Eh, not that dangerous". It doesn't take much for it to show true value. Flamestrike killing Pit Fighters? Frostbolts as powerful as fireballs for 2 less mana? Fireballs as powerful as pyroblasts for 6 less mana? I feel this is more of a silent threat: Doesn't jump out at your face as a "MUST KILL" target, but once the spell damage stacks up, your opponent WILL feel the pain. Yes, it's a slow card, which is why I said Arena, because there I think this guy really shines.

Had spell damage +6 on this guy in arena, Firelands Portaled them in the face for 11 and won. It was a while ago but I saved a screenshot, it was awesome :D

Does this stack? 

Yes. Also says so in clarifications under the card on this page.

I think that comparing this card to Ogre Magi and considering that this is a class card show that inspire mechanics unless really powerfull(like Confessor Paletress and Kodo Rider) should not hinder the minion that much, this card I think could be a 4/5 card that represents a possible threat, you need to use hero power which is a loss in tempo to make it slightly better than Ogre Magi(in the case it's a 4/5) and you would still have to use a spell to gain the value, limiting your choices as with Ogre Magi you could use up to 5 mana spells while this card would be limited to 3 mana spells. So in that case it would be the same power value for 2 turns compared to Ogre Magi which already is a card that doesn't see much use. But instead it's a 3/5 so I think it might be troublesome to make it work.

I just think Blizzard punished some cards like this one because of the potencial of other cards like Paletress and Kodo Rider which already have justified stats.But the thing is this card haves nothing to do with those other cards.Well, at least it kinda trades with Piloted Shredder.Which Ogre Magi doesn't.

As a 4 drop, this loses tempo to Water Elemental or Piloted Shredder. If this were 3 Mana 2/4, I believe it would see more play, considering mage turn 3 is usually aFrostbolt with a mana crystal left over, or Arcane intellect (not considering coin, in which case a turn 2, 2/4 with that text would be a huge advantage). Currently the 3 mana 2/4 goes to flamewaker, which never  sees play on turn 3, unless accompanied by the coin and arcane missiles / mirror image.

Quote from koooorah jump

 I believe it would see more play

I find it funny that you somehow know how much play its gonna get before TGT comes out.

its just a prediction

Quote from zomina1 >>

Quote from koooorah jump

 I believe it would see more play

I find it funny that you somehow know how much play its gonna get before TGT comes out.

Slow but if it does not get addressed it could become a serious threat.

That's am awesome art, might use it in a fun deck, thats about it.

Let's see how broken this card you suggest actually would be. 

Lowly Squire: This gives all your Lowly Squires +5 attack. Kinda dangerous...

Boneguard Lieutenant: Gives all your Boneguard Lieutenants +5 health. Just one of each gives you a 3/7. What

Silver Hand Regent: Now available: A neutral 1-mana Muster for Battle! That's fair, right?

Tournament Medic: Heal your hero for 10 for 1 mana and 1 card. We need good heals but that's pushing it too far.

Kvaldir Raider: 14/14 Kvaldir Raider anyone?

Mukla's Champion: Demonhearts for everyone! For 1 mana and 1 card! Not broken at all

Nexus-Champion Saraad: Draw 5 random spells for 1 mana and 1 card. Why bother with card efficiency when you can get all the spells in the world?
Recruiter: Draw 5 2/2s for 1 mana and 1 card. That's a lot, even if they are just 2/2s.

Kodorider: Imagine Grim Patron, but that can fill the board with 3/5s instead of 3/3s. Good job

Savage Combatant: Yep. Sure. 1-mana Pyroblast. That's fair.

Brave Archer: Slightly more conditional 1-mana Pyroblast.

Dalaran Aspirant: Oh look, it's a 5-mana 2-card Malygos in mage! What could go wrong?

Murloc Knight: 1 mana to trigger a version of Neptulon's effect. And summon the Murlocs for free. 

Spawn of Shadows: 20 damage to each hero. 20 DAMAGE TO EACH HERO. WHAT

Confessor Paletress: Move over, Aviana and Varian Wrynn. Now we get 5 random legends and Paletress for 8 mana.

Thunder Bluff Valiant: Though for totems only, this is 3.33x a Bloodlust for 6 mana, 2 cards.

Void Crusher: 7-mana 2-card Twisting Nether. Not soul-crushingly broken, anyway.

Orgrimmar Aspirant: 1 mana for 2.5x Deadly Poison in warrior. /endlesslyabusable

The only cards that can't use this very well are Coliseum Manager, Dragonhawk Rider, and Argent Watchman. Yeah. Only 10% of the inspire cards would be broken, that sounds about right. Right? Right?

This card would be balanced as a 3/5 with +1 (or even +2) spell damage without the inspire effect. 

yes!