Hearthpwn

I think hero cards should be allowed. Warlock has had one since forever and it currently doesn't break the game. Hagatha and Zul'jin also weren't very game breaking imho. I wouldn't allow quests in nun-quest expansions because I agree that they would look out of place in a lot of expansions. 

These cards are being over rated by player who are used to the old metas where card draw was rare. The current examples will see play if they are good enough without being tradable and won't otherwise. Now, tradable on expensive cards that cost 6+ might make a big difference. You could put higher cost cards in you deck without worrying about them clogging up your hand. Demon hunter might also love tradable on outcast cards. 

Firstly: It can be whatever you want! The stakes are low and a combined deck is something I would find fun. I'd just want it as a tavern brawl and not in standard.

For the sake of argument: Your version seems similar to an Archbishop Benidictus that affects both players. A rogue could create a deck that uses their weapon hero power and a warlock could create a deck that use their draw and self damage. For them, the game might still be fun.

But what about the other player? Once that affect activates, they will probably stop having fun. They want to play their decks and not a different one. They don't want to watch their opponent outdraw them and play their cards.

OP: Personally, I'd prefer it if the card made players draw from their opponent's deck after they ran out of cards.

My concern would be that this kinda mechanic would be unfun to play against. The card isn't op but it does kinda turn the game into pure rng. 

I would focus less on adding damage and more on giving the hero power other perks and creating inspire or after you have done x amount of damage with you hero power cards. Otherwise you're creating a burn deck that is either too slow or an absolute nightmare to play against.

Alakazam is very cool and also balanced but might be too frustrating to play against.  I'd change pugna to doing 2 damage to all enemy minions.

What if you had a card that shuffles all variants of Mulhouse into your deck and adds this to your hand once you play them all? It would not be a great card but if would get lots of style and flavor points.

Shaman has a tech spell that devolves minions. If you are having trouble with demon hunter, you might want to include it

The difference is actually motive in my opinion. Some of these characters are vengeful and therefore might go into demon hunter. Others are corrupted but still heroic. Nemisis is the God of vengeance and Kali just straight up hunts demons, Kerrigan is corrupted but still heroic, Huscar is corrupted and but still loyal. 

Warlock is for evil characters and demon hunter is for anti heroes and corrupted heroes. Rogues generally aren't physically magical.

No pressure, but if you want to make demon hunter cards, here are my ideas for what would work.

For Demon Hunter: Giratina seems to fit the bill. Dota: Mars, Snapfire, Huskar (best option), Vengeful Spirit. LoL: RIVEN. Smite: Kali (most obvious choice), Nemisis, Zhong Kui, Hun Batz. HoTS: ALARAK, KERRIGAN

No demon hunter?

These paladin cards are really cool designs. Minior is simple but interesting. At the moment paladin has almost no spell damage but that could change. Artanis would definitely see some play.

Atropos is very cool. I'm imagining a whole set of cards that work differently when priest is in shadow form. Would Atropos destroy 1 health minion in the opponent's deck or would they still be playable but die immediately?

Akali is probably too strong. Especially with stealth. Does Chen steal opponent's legendary minions? Otherwise he seems very weak.

Quote from Kiejdris >>

Yeah I was thinking about the same things

1. I dont think Carnunnos would be played in Wild just with Evolving Spores, too slow.

2. Ivern may be def too strong, I tried to compare it to Priest's Scream but yeah, Druid shouldn't get so good AoE removals.

3. I was thinking about giving Hoodwink either Stealth or Rush, but for Rush I thought it would be too strong and the amount of text looked ugly on the card.

4. Love the idea of Dormant on Aba, it would suit him so well! I just did the card years ago when this mechanic wasnt really a thing, now I would highly consider it to even be an all time Dormant.

 I'm sure you're right about Carnunnos. I forgot how busted wild is. I think Hoodwink would still be balanced with rush because it would need something weak to attack in order to be good. I wish there were more permanently dormant cards in hearthstone!