Yes for at least the first 2.

Too good on average. The first hero power (a free coin) is too good compared to how bad the second one is, while the other 2 are slightly better than normal because you can "save" them.

I have been working with my daughters on a Hearthstone set and I was hoping to get some more in depth feedback on some of the cards. The set has a "Mana Crystals" matter theme.

Chromie
Legendary Minion ─ Neutral
Every 30 seconds of your opponents turn Chromie gets +1/+1.
3/4
Everyone loves ropers. Just not as much as Chromie.

On summons: "Time is shorter than you think."
On attack: "Your time has come!"
On death: "Back to the future....."

Take that ropers and bots! Every 30 seconds she gets +1/+1. If your opponent finishes their turn at 25 seconds, doesn't trigger.

Kael'thas Sunstrider
Legendary Minion ─ Neutral
Battlecry: You gain 10 new Mana Crystals.
6/12
"What's better than 10 Mana Crystals? 20!"

On summons: "I shall give you a taste of TRUE power."
On attack: "My people must be avenged."
On death: "Nothing of my homeland remains, but ash and sorrow."

Yup, a whole new row of Mana Crystals (inactive, activating one at a time.) Specifically given 6 power to save him from BGH.

Rogue Card:

Ghost Blades
Spell ─ Common
Your weapon gains "Deathratte: Re-equip this weapon"

This would include any boosts such as Oil or Poison.

Mage Legendary:

We already have one for fireballs and one for Arcane Missiles, so I figured it was Frostbolts time.

"Iceman" Jones
Legendary Minion ─ Mage
Your Hero Power is Frostbolt.
4/5

I have a ton more but I wanted to gauge interest first. Now time to peruse the gallery.

The first is a bit too much above the current budget-line. It's also a mechanic they probably wouldn't do again. They've already had a severe number of headaches (and likely regrets) because Nozdormu is a 9 mana card in the game.

I don't like Kaelthas either.

Ghost Blade is decent. The 4th one is probably okay too. I would be happy with both making it into the game.

I don't like the names.

Thank you for the feedback. The names are just place holders for now.

Gifted Treespeaker
Epic Druid Minion
Whenever you gain a Mana Crystal draw a card.
3/5

I'm back and forth on the health being 4 or 5.

Life Juggler
Rare Neutral Minion
Whenever you cast a spell heal 1 damage from one of your damaged characters.
2/3

- Wasn't sure if this should be the inverse of Knife Juggler, or the inverse of Pyromancer where it heals 1 from all my other minions.

Infernal Power
Epic Warlock Spell
Destroy all your mana crystals.
Draw seven cards.

Ironforge Challenger
Legendary Warrior Minion
Taunt. Whenever this minion is dealt damage draw a card.
4/6

Stormwind Blacksmith
Rare Neutral Minion
Battlecry: Repair your weapon.
2/3

I think a lot of these designs are trying too hard to be different and mess with the game mechanics.

Also infernal power is the worst card ever and would never see play. Maybe in zoo actualy.

I'm curious on which game mechanics you think I'm messing with? Kael'thas I'll give you, but even that's not really messing with anything to crazy.

Chromie. 2 is "a lot" apparently.

Envenom Blade
Common Rogue Spell
Your weapon is poisonous.

It gets the little potion bottle and kills anything minion it damages. The cost was hard for me on this one. I had it at 1, but then I think it invalidates Deadly Poison a lot of the time. Would 3 be ok?

Blackheart the Inciter 4
Legendary Neutral
Battlecry: Deal 1 damage to each minion you control with enrage
Enrage minions you control get +1 health
4/4

Golden Monkey effect should have been: For the rest of the game, Discover a Legendary at the start of your turn instead of drawing a card.

that's so much more work though

Fatigue is a good thing.

Golden monkey should replace your deck with 23 legendary cards and your hand with 7

At the very least, I'd rather it didn't replace the cards in your hand.

Best slowroll ever though: One card left in deck (Map to the Golden Monkey). Soulfire in hand. Opponent @ 3 life. Life Tap into the Map, play the Map for the Monkey, Soulfire discarding the Monkey for the win. And my friend was spectating me too!

Seriously though I crafted a golden Elise and I wish that investment had been better spent. #noregrets because it's basically my favorite card, but I think it could have been even better.

You don't need a card in hand to play soulfire though so that's silly.

Deep Chill
Mage Spell (Rare)
Freeze all enemy characters that were Frozen last turn. Draw a card.
Hope you packed warm mittens.

Ring of Frost
Mage Spell (Epic)
Choose an enemy minion. Deal 4 damage to all other enemy minions and Freeze them.
Jaina never figured out how to fill in the hole in the center.

Night's Whisper
Warlock Spell (Common)
Draw two cards and take 2 damage.
Darkness calls.

Rain of Chaos
Warlock Spell (Epic)
Deal 3 damage to ALL minions. Summon three 6/6 Infernals.
Why stop at two infernals?

Night's Whisper is nearly strictly worse than their hero power.

It draws two.