Probably best in Mage and Paladin.

Wow, immediately got me thinking about Malygos Shaman where you can speed up collecting the combo, but it's probably more "food" for cyclone mage. We will see about other classes - Warlock could get Spirit Bomb or Grim Rally I think, Warrior gets Whirlwind or Upgrade (which could be sweet), Priest has Inner Fire and Cloning Device - these all look interesting! 

This seems almost too good for Dragon Priest and Mage. Since you can get cards like Inner Fire, Power Word: Shield, and the new card Arcane Breath.

This has Mage written all over it. Could be slotted into a Highlander Paladin deck to get more secrets, though there are some shitty 1-mana spells from that class. 

Mage is the undoubted winner with this card, but Priest and Warrior are also quite well off. The others are lackluster - Paladin can find a variety of secrets, but none are amazing, and I doubt Dragon Secret Paladin will exist. Shaman has damage, but dragons in Shaman seems odd so far.

Interesting card, especially in arena!

Waaay too expensive and not enough value for standard pretty good arena card though

Pretty good when you have a plan with cheap spells, like having an Auctioneer.

Looks like an Auto include into both mage and pally decks.

The value comes from how good a classes 1-cost spells are. Which even if they are on average pretty good, still means you need to recoup some good tempo and value from those cards. This is about 2 mana behind on tempo, so you're only getting exactly what you pay for, but if you really want that, or you really need an extra dragon I guess it could work, but generally speaking I think this will ride the sidelines.

When it comes to 1 mana spells, not every class are equal ...

After looking at all the standard 1 cost spells for each class, it seems like mage is the best class that is able to properly use this effect. All mage 1 mana spells are flexible enough to see some use except for Learn Draconic, but that card can work in a big spell dragon mage deck with Dragoncaster.

We have Priest and Warrior that would be at second. They both have some good 1 mana spells while having some that can be more situational like Inner Fire and Into the Fray. They also have some decent dragon synergies.

After that we have Shaman at third with lots of 1 mana removal spells, Lightning Breath wouldn't mind having more dragons to help make a dragon shaman deck and it's a battlecry card which could work with Corrupt the Waters.

Paladin has a high chance of getting some secrets out of the battlecry, but I don't think that a secret paladin would want this card since it's such a weak tempo play and a slower dragon paladin deck wouldn't want secrets.

The other classes have too many situational 1 mana spells to make Cobalt Spellkin work. So I think that this card will only see play in either Mage, Warrior, Priest or Shaman.

It is an interesting card, it might see some play in cyclone mage or maybe miracle rogue. I think being a 5 mana 3/5 it will probably be too wonky to play. But I glad to see this as a card, adding spells to your hand was never really something you could get from neutral. 

It probably will not find a home in any competitive decks, but I know that players like me who enjoy playing with sub-optimal cards will end up playing him somewhere. And this will also be a nice inclusion to my casino mage.

Slow Burn Quest Mage? Seems too slow to be viable.

Chenvalaa support for mage, secret generator for pally.  This card will definitely see play.  3 stars

The usefulness of this in Cyclone Mage or Secret Paladin is obvious, but I have a hunch this will see play in some other classes.

It's not immediately obvious whether or not this can pull quests. Some cards like this have omitted quests in the past, and hopefully this will also, as getting a quest your deck isn't built for is going to feel really bad.

"Drawing" two cards is worth 3, and a 3/5 is certainly worth more than 2, so the back-of-the-envelope math suggests this card is good. The tough thing is that it's so low tempo for the turn you play it, and you could always just include a particular 1-cost spell you want in your deck instead, so the bar for entry into any deck is a little high. To see play, Cobalt Spellkin needs a dragon deck (because this probably sits in your hand activating your better dragons) in a class that either a) gets value out of having cheap spells regardless of their effects, or b) has mostly great 1-drop spells.

Obvious contenders here are Rogue (where the 1-drop is at least a combo activator, and might also be a useful card), Warrior (where the pool of 1-drops is small, and chocked full of good stuff), and Mage (basically the same argument as Warrior, with the added bonus of spell-casting synergies). I don't think any of the other classes get enough value out of this to be excited about it.

The fact that this is a 4-cost (edit: oops) dragon that can viably be dropped on turn 4 is not something to overlook.  Something that most dragon decks would love is dragons that don't clog up your hand all game, because they're either situational or expensive.  There are very few dragons in standard, especially neutral ones, that you don't mind playing on turns 3-5.

Probably would see play with things like gadgetzan or the new Mage legendary, doubt it’ll see much play for the effect alone

The fact that you can get quests from this is insane. Works best in Mage and Paladin

Missing the blue border is definetly good in mage, need to check which class has a limited pool though, having more shield slams is relevant. 

Also if someone thought about using the druid claw side quest for some cheap spells to cycle, this is just better.

Stats are not good for 5, and the effect is a bit limited in standard. But for some classes will play it in their dragon decks to fill the holes. I like it though.

Possibly useful in some Dragon Highlander deck.

But generally too slow, and not reliable enough.

A good value-generator. I can see this seeing play in niche decks. Card is pretty strong imo.

Super bad stats for this card, I don't really see this getting any play outside of maybe some use with cards like Chenvaala. It is interesting how this card can give you any of the new 1 mana sidequests. Here are a couple good hits from each class:

Paladin could get a couple secrets and cheap buff cards.

Mage has a bunch of nice 1 mana spells.

Druid has Floop's Glorious Gloop, Worthy Expedition.

Hunter has Tracking or Secret Plan.

Priest has Power Word: Shield, Mind Vision, Cloning Device, Holy Smite and Embalming Ritual.

Rogue has Togwaggle's Scheme, Deadly Poison or Pilfer.

Shaman has Lightning Bolt, Earth Shock and Blazing Invocation.

Warlock actually has lots of good hits, namely Mortal Coil, Plague of Flames and Soulfire.

Warrior has Shield Slam, Omega Assembly and Devastate.

This is just some of the cards it can give, it certainly is a decent card but I don't think you will ever dedicate a deck slot to include this guy. Probably only see play in decks which can abuse 1 mana spells or found through discover and random effects.

fun in arena and also a dragon.

Maybe there's some funky dragon and/or Spell/auctioneer deck that needs some extra generation. 5-mana 3/5 that generates 2 cards that are useful.

This card is insane! For a wild druid, it might even get them back their Jades, after the 1cost spells were burned from the deck....

A very fun card. It would be pretty nice to get a quest card from it sometimes! There are a lot of good 1 mana spells from different classes, but this card is too slow and situational to be included in any deck IMO. But i'd would be glad to see it played on ladder. I'll try it out for sure.

a neutral card that only fits with some classes, not very impressive

Quote From Elfensilver

This card is insane! For a wild druid, it might even get them back their Jades, after the 1cost spells were burned from the deck....

Yeah it might but there are too many druid spells (17) in Wild to make this card worth to include IMO. The chance to get what you need isn't that high even though 2 of those spells have a discover effect.

The variance of 1 cost spells is way too high, to make this work consistently. Also what you get depends on your opponent. So this is a 2 star card at best

The type of card that has a ton of potential but I just don't see it at first glance. I guess it will be better in classes with smaller 1 mana cost spells pool. In the end it may just be spell fodder for mage

This card is super interesting! 

In mage the 1 cost spells in standard are pretty good, highlander mage was waiting for another strong dragon to run to reach a good amount of them, with this card they finally reach this goal. They can run New Maly, old Alex, New Alex, Kalecgos and this one. If they find that activating Maly is still a bit unreliable they can add the 2/3 dragon and/or twilight drake.

Another class that has good 1 mana spells is warrior, so it fits there, especially because warriors can play a control dragon deck and this can give you removals or lackeys or the omega card. 

The only downside of this card, which seems to be a common theme of these dragon decks, is that is not a card that threat your opponent in anyway it just generate value. So i can see this card being a 1 of in decks that will run 7-8 dragons

I'm not a really big fan of this card. Losing to this will feel so bad, while getting useless results also feels bad.

great card in STD for warrior, priest and mage but i think in Wild sucks

Quote From vprr

Super bad stats for this card, I don't really see this getting any play outside of maybe some use with cards like Chenvaala. It is interesting how this card can give you any of the new 1 mana sidequests. Here are a couple good hits from each class:

Paladin could get a couple secrets and cheap buff cards.

Mage has a bunch of nice 1 mana spells.

Druid has Floop's Glorious Gloop, Worthy Expedition.

Hunter has Tracking or Secret Plan.

Priest has Power Word: Shield, Mind Vision, Cloning Device, Holy Smite and Embalming Ritual.

Rogue has Togwaggle's Scheme, Deadly Poison or Pilfer.

Shaman has Lightning Bolt, Earth Shock and Blazing Invocation.

Warlock actually has lots of good hits, namely Mortal Coil, Plague of Flames and Soulfire.

Warrior has Shield Slam, Omega Assembly and Devastate.

This is just some of the cards it can give, it certainly is a decent card but I don't think you will ever dedicate a deck slot to include this guy. Probably only see play in decks which can abuse 1 mana spells or found through discover and random effects.

Very nice list. Don't know if it could have relevance but hunter also has some ping spells whose extra generation could be abusable in a Malygos deck.

Of all classes, warrior could potencially be the one to make the better use of this card, since it has the smallest 1 mana spell pool and most of them are control or card generation tools. In a control dragon deck this card has the potencial to be the "new" Omega Assembly in terms of card generation and opponent hate.  Warrior still is one of the few classes that can afford to waste 5 mana in a weaker body in order to prepare for a future better turn.

An interesting card that i'm sure will find a place in at least a couple of classes - looks perhaps most promising in Secret Dragon Paladin?

Not sure if this will fit in a deck, but it's a pretty cool battlecry

Good value and it's not that slow, with good enough stats. It's great that it's a dragon because any tempo loss can be made up for with the new broken cards which synergize with dragons, plus it can be discovered easily. The 1-mana spell pool is limited, but powerful for a number of classes, notably mage.  I just hope it can't give you quests!

As a mage player this is very interesting, since you really want extra 1-mana spells to combo with either a cyclone package or an Archmage Antonidas turn, but you do not want a deck that only consists of spells since you obviously also need some bodies on the battlefield. Together with a dragon tag this is also an activator for various other cards while in your hand. So I can see this find a way in some mage decks.

Arena filler and possible playable in quest mage.

I wonder what the rouge 1 cost spells are?

pretty good effect and it comes with a nice body ( ͡° ͜ʖ ͡°)

Really strong in arena. In standard I can immagine to play it only in mage for Cyclone package

Too weak to be played on turn 5? Depends on how much you need those spells. Cyclone mage or rouge might choose to Discover this.

In some classes it may find place. Maybe Gonk Druid to get more claws? Or cyclone mage, to gain cheap spells? Overall decent card.

too slow and rng for useless 1 cost spells? no thanks..dust approved.

Nice, but I don't think this is going to see play.

Possibly used to fuel cyclone mage, but it seems a bit too slow.

The dragon tag in this expansion is very valuable so if it will ever find a home in a deck it will probably be mostly for that.

I rated  this card only 3 stars, but that is because not all classes will use it equally. Most people have already pointed out that this benefits Mage in trying to get the cyclone archetype going. Priest, Warrior, and Shaman might all get some decent use out of this. There are too many secrets and situational cards for Paladin to get consistent results from it. I wonder if the development of this card is what pushed Naturalize into the Hall of Fame.

Good addition for my Golden Quest Mage deck. This being Rare I might even craft it...

Very interesting card for Gadgetzan decks to gain more draw. Looks promising for priest or mage with cheap spells.

Nice option for Dragon Handlock if you want more dragons in your deck.

I wonder if it can give you quests tho.

This is going straight in Reno dragon mage for more value.

Fun card in spell mage, will see some play.

Pretty strong card in Mage or Druid, but not strong enough for every class.

feels like a underrated card but might be good

By my count, we have only 5 in druid currently which is a 36% chance to get at least one copy of a specific one-cost spell you were hoping for. That's pretty consistent if you ask me. Or go paladin so that your opponent has to try to play around any of a bunch of random secrets.

Cool unique battlecry, but I expect it to be too slow

Reminds me of Arcane Dynamo in the sense that it will usually give you specific spells and so there might eventually be something cool to do with this, currently getting extra Sidequests. Much better stats than Dynamo though, but 1-cost spells usually have much smaller impact.

cheap spells are nice and nice bodies are also nice fairly curveable I think this will be played quite a bit

This card could fit into Cyclone Mage, but 5 mana is rather expensive. Since most side quests cost 1 mana, this card can also some of these powerful spells. I don't think that this card will see a lot of play, though.

There’s quite a few new 1-cost spells, including all the Sidequests. Rogue and Mage stand out though, with Rogue being able to make Legendary minions from Dragon’s Hoard and Mage having access to Chenvaala.

Probably sees play in reno dragon decks, and maybe also cyclone mages

This looks o

This is a great and interesting design. I love the Oprah reference when you put it on the field "You get a spell!" - as trump pointed out. 

Deffo seem strongest in mage, but really not bad in any of the other class. Should be considered in all dragon builds I think.

Great neutral card. There's a lot of useful 1 mana spells in every class. The obvious choice being Mage. Being a Dragon it may find home in Dragon decks too.

Also pretty good in arena.

Solid card, seems to fit mage the best.

So, here's complete list:

Druid:

Claw, Savagery, Biology Project, Floop's Glorious Gloop, Crystal Power, Untapped Potential, Worthy Expedition, Secure the Deck, Strength in Numbers, Treenforcements

Hunter:

Arcane Shot, Tracking, Bestial Wrath, Secret Plan, The Beast Within, Rapid Fire, Unseal the Vault, Clear the Way, Toxic Reinforcements

Mage:

Arcane Missiles, Mirror Image, Tome of Intellect, Shooting Star, Magic Trick, Ray of Frost, Raid the Sky Temple, Arcane Breath, Elemental Allies, Learn Draconic

Paladin:

Blessing of Might, Hand of Protection, Humility, Blessing of Wisdom, Eye for an Eye, Noble Sacrifice, Redemption, Repentance, Hidden Wisdom, Autodefense Matrix, Crystology, Desperate Measures, Never Surrender!, Making Mummies, Righteous Cause, Sand Breath

Priest:

Holy Smite, Mind Vision, Power Word: Shield, Radiance, Inner Fire, Cloning Device, Activate the Obelisk, Embalming Ritual

Rogue:

Deadly Poison, Sinister Strike, Pilfer, Daring Escape, Togwaggle's Scheme, Bazaar Burglary, Plague of Madness, Dragon's Hoard, Praise Galakrond!

Shaman:

Frost Shock, Earth Shock, Forked Lightning, Lightning Bolt, Blazing Invocation, Voltaic Burst, Totemic Smash, Corrupt the Waters, Invocation of Frost, Storm's Wrath

Warlock:

Corruption, Mortal Coil, Soulfire, Call of the Void, Dark Possession, Soul Infusion, Spirit Bomb, The Soularium, Grim Rally, Shriek, Plague of Flames, Sinister Deal, Supreme Archaeology, Rain of Fire

Warrior:

Charge, Whirlwind, Shield Slam, Upgrade!, Omega Assembly, Devastate, Improve Morale, Hack the System, Into the Fray

good neutral value generator. mostly usable in mage, maybe also rogue

Pretty great value to add two cards to your hand like that.