Hearthpwn

• You have 4 cards with 4 lines in the basic set which is too much. Basic cards rarely if ever get to 4 lines, you should have done things more simple.
• Complaisant Server and Grand BBQ is an easy 9 mana OTK that doesn't require much setup.

• I think the text on Sand Blast shouldn't say "Next time you play this card" as that leads to confusion. You cannot replay the same card, you only play other copies of Sand Blast which isn't the same thing.
• Blessings of the Bronze is arguably a better Sound the Bells!. It does only give 1 Health but it costs 1, making it an unconditional symmetric buff. It's Blessing of Kings, unconditional Bloodfury Potion, Demonheart. Acting as a 2 mana +2/+2 and 1 mana +1/+1 is a bit worse than average but from 3 mana onwards it's just better. Plus it's flexible.

• If you have to shrink the card text by more than -4 or -5 to fit then the text is too long and needs reworking.
• Path Finder does not specify if the shuffled cards are random, thus leading to the idea that you could choose which ones, something not possible in Hearthstone sadly.

• I still believe The Plague is worse than Poison Seeds and Twisting Nether.

Nothing to say, i think everything is balanced.

• My main criticism is your Keryword. It works fine as an *expansion* keyword, but as a class one it's kinda bad. Lets look a bit at class keywords in game: Combo is a condition for an effect, Choose one is a choice between 2 effects, Outcast is a condition for an effect, Overload is the only bad one, like all shaman things in general, but it acts as a drawback to powerful effects. You get the trend? None of them are things in of themselves, but conditions for other stuff. How is infected going to work out? You'll have cards that infect minions, ok, but they all do the same thing, they won't be original. What i'm trying to say is that it's too limited, it doesn't allow for innovation. It's not the condition of something cool to happen, it IS the "cool" thing that's happening.
• The mill cards are fine but i believe they won't be received well by the audience, mill decks are pretty hated by the community at large.

I must say you are my favorite class. Having a named token and interacting with it is an awesome idea which i am totally not gonna steal for future comps.

• Lightning Blast is a better Shiv
• Next Guardian is a worse Midway Maniac

• This might sound nitpicky but i don't really like your card arts. They don't have a constant style, they vary wildly from hyper realism (Shot Right Through, Double Barrel Shotgun) too goofy cartoony (Orc Agent) and anime (Laser Ray). You should try to find a more cohesive visual style. I'm not one for sticking strictly to the hearthstone style but the cards should at least be similar in style with each other.
• Reckless Rookie is a better Redgill Razorjaw

Everything is fine

• I'm not a fan of minion armor as it just seems like overly-complicated bonus Health but we'll see
• Keep in mind Stern Observer cannot be targeted by your hero power either
• Protective Shield is a worse Barkskin
• Water Warden is a bigger Scarlet Subjugator
• Power Surge is just Blessing of Kings though i assume the armor will have more interactions. Still you could have made it a 3 mana +3/+3 or 4 mana +3/+5 to differentiate a bit more.

I don't want to sound harsh as this seems to be your first... post on the site lol. Hope you actually read this. Please use the discussion threads before posting, you have a lot of issues, and i don't want to discourage you, i like your enthusiasm so don't read this as me belittleing you, i just want to help.

• Your Hero Power is bad. Toki in the adventure had a lot of RNG cards that had, well, random effects, and so you could rewind to try the RNG wheel again in hopes of a better reward. You have no randomness in your cards. And besides all that, the hero power is weird and not much use. Look at basic hero powers in general, they all can be used to generate a small effect. Deal 1 damage, restore 2 health, draw a card. When would you use your hero power? It's too niche.
• Run the Clock is bad. I understand what your intentions were, to have the Nozdormu effect on at all times and benefit from it. That is not a bad idea but think of how players will most likely use this card: they will wait until the rope is burning. This is one of the most toxic and hated things in the community, they even have a term for it, roping. You can find endless threads complaining about players roping to annoy their opponents, and this card promotes exactly that.
• Rewind is technically a better Recycle as you not only remove the minion from the board, but you deny them a card draw. It costs more than Sap but not letting the enemy draw a card is well worth the 2 extra mana.
• Reset is a more expensive Vanish... as you yourself pointed out. Why copy an existing card and make it worse? At 8 mana it's a worse Twisting Nether, and Vanish also had Preparation to make it even cheaper.
• Bronze Dragon Mount is not a bad concept but a turn in Hearthstone lasts 75 seconds. The rope burns when there are only 20 seconds left. The vast majority of opponents can play just fine in 55 seconds. Nozdormu itself was not really played cause 15 seconds was enough for most opponents.
• The idea of reducing enemy turn duration is in of itself a touchy subject. It might annoy combo players and control players, and in general it feels bad for the opponent.

Don't take this criticism to heart, you did some great stuff too. i like the pocket watch and Clockwork Keeper, i think you should go more into this direction.

• Same criticism as Klaytonio, your art styles are all over the place. Stitcher Ghoul uses art of an existing card (Ghoul token from Arrogant Crusader, Val'kyr Soulclaimer, Necrotic Geist and Vryghoul. Endless Death is just a crop of a pixel art weapon with a blank background. Invoke Darkness looks like someone left a red ink stain on the card.They don't look good together.
• "Summon a new copy" is worded wrong, the "New" isn't needed.

Is balanced.

• Tricks of the Trade doesn't need you to have a weapon to cast it, so it is very often a straight 2 mana Arcane Intelect. You should have said "Destroy your weapon to draw 2 cards"

It fine otherwise.

• Backstreet Cutthroat is a bit too strong. Compare to: Dispatch Kodo, Troll Batrider, Fire Plume Phoenix

• I think it would have sounded better if you named theme "Ritual Tools". Ritual dagger, Ritual Magic, Ritual Figurine, Ritual Mixture.
• Toadmancer is better Eggnapper

• Hero Power seems a bit reckless. This class will die to fatigue super fast, i'm not sure how you intend to proceed with it. You can't rely on any combo or control playstyle cause you burn random cards from your deck with every tap. Not sure how you will balance this.
• RIP Dessicate, power crept by the latest card reveal. Touch of the Nathrezim
• Essence Burn is weaker than Drain Soul and Penance.

Seems fine. Air Strike might be too weak compared to Explosive Shot and Power Shot

Seems fine though idk how much you can innovate on the stylist idea to make a whole set and an expansion.

• Sharpen is unclear. Are the minions random? if you don't mention the word then it means you get to choose, including for the deck and hand which isn't possible in Hearthstone.
• Strongest isn't a thing in hearthstone sadly. You have to say highest attack or health or cost.

• Excess Chitin is a stronger Iron Hide

It's fine otherwise.

• Dragon Queen's Enforcer and Heat of Battle are cards that set the tone of Attacking Synergy within the class. The obvious and intended card to combo them with is Unleash the Whelps! but Scaleborns will have other ways to generate large boards and attacks with their minions.

• Family is a core theme of my class, and i think everyone knows about that cool and weird uncle you only see at family gatherings and holidays trope right? :D
  He will give a random Heritage to each minion you summon, meaning gaining one of the Keywords.
• Onyx Twins are another family themed card that also plays in the Attacking Synergy by giving you 2 Rush minions.

• Drawing is one of the class' strengths and so here we have two similar cards but with very different purpose. Spread Your Wings gives Rush to anything it draws and lets you get that minion into the fray right away, enabling Attacking combos with cards such as Heat of Battle.
• Mating Ritual is more value oriented however, refreshing your Hero Power, thus generating you another Heritage card this turn. Being a tribe specific tutor also lets you draw a certain minion for special combos. Dragons be horny man.

• Due to the card generation of the Hero Power, the class has easy access to big hand synergy and that aspect will exist in some of the cards.

SCALEBORN

Born of love unnatural, of both man and dragon, these knights inherit powers of the 5 flights within their very blood. With a family unlike any other, they rush into the fray, not giving the enemy any break. A ceaseless charge of a well aimed and prepared horde of dragons and riders, the apex of aerial combat.

Core Themes:

• Dragon Ancestry: From being able to partially shift into a half dragon form, to using the full power of the magic granted to the dragon flights by the titans, Scaleborns show a unique combat style of merging knightly cadence and tactics, with the raw power of a charging dragon from above.
• Family: A scaleborn has the weirdest and most interesting family tree of anyone in Azeroth. Some of the cards will show these core theme of family, and the self discovering journey you will take to discover your real ancestors.
• Swarm Tactics: Unlike the dragons we've seen before in hearthstone, Scaleborns take them to a new, aggressive level, focusing on Attacking synergy and proactive mechanics.
• Tactics and Plans: The Hero power and connected Heritage cards let you plan ahead and empower your minions before playing them. This keeps true with other cards that prepare the field in advance, so when your flight finally descends they are in the best conditions for the win!

Strengths:

• Sustain and stickiness due to Heritage cards
  
• Card Draw
• Wide Boards
• Strong Buffs, but held back by RNG
• Adaptability and Tools for any situation

Weaknesses:

• Recovering a lost board
• Late game threats
• Unconditional board clears
• Family Gatherings >_>

• First things first, great art, it really fits the Hearthstone style well.
• The Specimen card has a way too weird name. I get the reference but it is weird to have a real date in a card name, and a lot of people won't get the reference. Also i think the wording is wrong. The way you phrased it, the "and this deathrattle" bit is tied to the "Deal" verb. It should be "Deathrattle: Deal 1 damage to all minions and give them this Deathrattle". Which i think it's OP by the way. Can easily turn into a 2 mana full board clear.
• Assessing Symptoms on the other hand is too weak. the -2 health is just Deal 2 damage, and the -2 Attack is pretty weak. For a 5 mana card and the fact it's random, it's too expensive. Could even be 3 mana imo.
• Not sure Fatigue cards are allowed in the basic set
• Pestered Mice is a better Kobold Apprentice. I think it should be 4 mana with the added lifesteal.
• Slimepalooza is OP. It's a full board clear for 5 mana, Twisting Nether cries in the corner. Staff of Scales is a treasure in duels and it's supposed to be an OP card better than anything they'd ever print for real. Look at Webweave.

Overall great job at capturing the character in a class but you need to tone down the removal and aoe a bit.

• Nice hero power, good balance between mage and paladin.
• The Plague is weak. Poison Seeds for reference.
• Wrath of the Plaguebringer could be 1 mana since Corruption has a similar delayed effect and it straight up destroys the target.
• Flask of Death is a neat design.

Now you just need minions that you'd wanna kill with all these sacrifice mechanics.

• Sand is a weird name for a spell school, but not sure what else it could be called.
• I liked the name Accelerate better
• Adept Chronomancer is neat but i fear it will be an auto include in the class... forever. You'd never want to not have 0 mana 2/3 pseudo coins, no matter what deck you're playing. Plus they could easily make the class feel too oppressive with the bounce synergy.

And as a reply, i could make the Heritage cards the class mechanic, kinda like Spare Parts, but idk what the hero power could be to capture the same flavor. 5 hero powers that change every turn is also a bit too much for a basic hero power. I'll think about it.

• The first Heartbane Ritual art looks like what it would be the starting version and the second one is what Blizzard would nerf it to like they nerfed Jaina and Secret Keeper kappa
• Return to Life 3 is High Inquisitor Whitemane. the 4th version is anti board clear which is unfun. I like the first version tbh, also you could rename it to "Corpse Run" to be a more direct reference?

Not much else to add, like others said be careful to not turn into priest 2.0

• Cool hero power, might be too snowbally if the enemy can't deal with it early.
• Toxic Fangs is worrying me a lot. Dealing 3 damage to anything for "free" can easily turn into an OTK, also Auctioneer since you like bringing him up so much :) . With Excess Chitin that is 9 damage for 3 mana in 2 cards, the strongest in the game i believe. Mage can do 7 with Frostbolt and Ice Lance. Can be 12 damage if you have 1 Armor previously.
• Crypt Queen allows for an OP combo with Toxic Fangs. Just hit her over and over, amass more armor than you lose, then start spamming face like Raza priest.

• New cards are much better, Stalking is very cool.
• Dynamite Shot is a tad too strong as it's essentially a better Shadowbolt if you target a minion.
• Without hand buffs, Bilgewater Goon might be too weak