Objective: Control the board with spell damage minions to enable efficient removal of enemy minions, thus maintaining board control. Deplete opponent's hand by using cycling cards such as Starfire with extra spell damage to remove large threats, and deal with smaller minions with Swipe or Wrath.
Win condition: Reach a point where the opponent is no longer able to do anything about your board control due to lack of cards in hand.
Moonfire: Usually a substandard removal card due to its low damage often making it a two for one. In this spell damage deck, however, it can be very useful. +1 spell damage turns it into a Holy Smite / Arcane Shot but for zero mana. This means that it combos well, particularly with the Kobold Geomancer. More often than you'd think, the opponent plays a two mana 3/2 on turn 2, and I simply throw out the geomancer and moonfire it.
This has two effects. One, you killed off their minion without loosing any tempo (as moonfire is zero mana), so it puts you in a controlling position. Secondly, it is unlikely that they will be able to kill your geomancer on their next turn, so you get the spell damage for another turn. This is just one example, and there are many more combos you can do.
Ancient Mage: The effective +2 spell damage of this card can be extremely useful. I hardly ever see this card used, and with good reason: it is only suitable for a heavy spell damage deck, and it requires two minions on the board to work to its full potential, and is a horrible card to play on its own. But I think at least one is suitable in this deck; I almost always have at least two minions on the board, and it works with my spells very well.
Ogre Magi: This thing is awesome. A chillwind yeti but with -1 health and +1 spell damage. Totally worth it for any spell damage deck.
Starfire, Starfall: Excellent removal. Starfire cycles itself, so if you kill something with it, you gain card advantage, and killing something with it is easy with dpell damage. Starfall is very versatile; I use it about half the time for direct damage, and the other half for AoE. The latter scales extremely well with spell damage.
Swipe: The core of this deck. An excellent card in any deck, but it gets better. This card scales extremely well with spell damage. With +1, it's a Consecration but you get to nuke something for an extra 3 as well. With +2, it's a hellfire that only affects enemies, plus a 3 damage nuke. With +3, it's a flamestrike for three less mana, plus a 3 damage nuke.
Wrath: Really good early game control. It can be a Frostbolt (minus the freezing) or the mage's hero ability. Good in any deck, but excellent with spell damage. It very often kills a minion while drawing me a card.
Cards which I would like to put in but don't have :(
Malygos: Need I explain? Would replace one ironbark.
Starfall #2: Could do with some more AoE, and this card has the added option of a nuke as well. Don't know what to replace.
Bloodmage Thalnos: A geomancer but draws a card. Excellent. Don't know what to replace.
Azure Drake: Ogre magi but cost one more and draws a card. The magi is already very good, and this is even better! Would probably replace one of the magis and one archmage.
Feedback in appreciated. I would like to know which cards you think I should put in, and which ones I should replace them with. Is there anything in there that you don't think is serving any purpose? Do you think another card would be a good addition? Please let me know. And by the way, I've only had the beta for a week, and don't have any legendaries, so no sylvanas for me :(