This is only good at mid game, if this is the only card you have on turn 4 you are pretty screwed (because I'm pretty sure you didn't invoke twice by then)
5/5, since it is a discover effect you can dodge those pesky legendaries that have synergy with elementals, beast and other things your thief rogue doesn't have.
I like that it's a neutral. Definitely a good fit for a shaman, warlock, or druid token deck. I think the low attack is a fair tradeoff for something that fills your board every turn until its dealt with.
Umbral Skulker
This is only good at mid game, if this is the only card you have on turn 4 you are pretty screwed (because I'm pretty sure you didn't invoke twice by then)
Learn Draconic
I think this can get a home in secret mage.
Sathrovarr
"Welcome to value town, we have special deal! 3 for the price of 1 (or 9 mana)"
Dragonbane
Fun card, for some reaason I find it really weird that it can attack normally. In my mind this kind of cards don't attack like Ragnaros or Gunspire.
Dragonblight Cultist
Zoolock Galakron could be a thing but I just don't see it.
Devoted Maniac
If you ignore that the invoke will trigger galakrons ability, this has really bad stats.
Fate Weaver
Even if you haven't invoked twice, the stats on these are pretty decent to add in a dragon deck.
Time Rip
4 power minions, you are going down!
Toxic Reinforcements
THE FACE IS THE PLACE!
Too slow when drawn late in the game.
Azure Explorer
i'm not tottaly sold on the cost and passive, but discover a dragon is always powerful.
Primordial Explorer
Good stats, good passive, good battlecry, good card.
Malygos, Aspect of Magic
Good and Fun card, good to see that it will push dragon mage back in the game.
Deathwing, Mad Aspect
All will burn, but this time your cards in hand won't!
Waxadred
Copy it and double its deathrattle for fun times!
Corrosive Breath
2 mana do 3 to a minion is pretty good even if you don't have a dragon.
Sand Breath
I don't feel like the long run effect is good, it seems better with a fast aggro deck, but those don't have dragons so......
Candle Breath
Even if rogue dragon does not work, this is instented to work with dragons, which makes it a 3 mana draws 3, which is pretty good.
Dragon's Hoard
5/5, since it is a discover effect you can dodge those pesky legendaries that have synergy with elementals, beast and other things your thief rogue doesn't have.
Molten Breath
Knowing that with the new Galakron you'll be hitting stuff way more, this extra armor seems pretty good.
Nozdormu the Timeless
I'm still not sure about it, I like that at the beginning it just boosts both players and at the long run it's a 4 mana 8/8.
Dragonrider Talritha
I started in RoS playing a dragon pala, this will surelly make me retry it again.
Envoy of Lazul
First of all, fun card, second, it'll get way more misses than Glimmerroot which makes it a worse card.
Secure the Deck
If there was a simpler way to complete it in one go it may have been better but the new quest makes it even MORE difficult to complete this.
Warrior Legendary Galakrond Reveal - The Unbreakable
In combination with Upgrade!, Armored Goon Sul'thraze and Akali, the Rhino this card has the potential not only to revive Tempo Warrior, more like evolve it to the next level.
New Neutral Minion - Shu'ma
I like that it's a neutral. Definitely a good fit for a shaman, warlock, or druid token deck. I think the low attack is a fair tradeoff for something that fills your board every turn until its dealt with.