Hearthpwn

Wrathful Wrathguard: Since the introduction of Wrathguard in TGT, this card's name was taken, and that's no good. With the original 2/4 statline it didn't feel aggressive or contesting enough to do much good in a viable Warlock deck— as a 4/3, it is more aggressive but also punishes high-health and high-Attack minions.

Soulwell: At a 3 mana 0/4, Soulwell was very easily contested and could be gotten rid of with few problems. With 7 Health it provides survivability for the effect, with less of a soft-Taunt effect than Doomsayer.

Zealous Shivarra: At 3 mana this card seemed unplayable, but the text also made it a 4/2 on the turn it was played, which was useless as it did nothing because it couldn't attack. This makes it more viable for a Wild token Warlock/zoo deck.

Shielded Outcast: The original card actually didn't do anything much, as it couldn't attack, and when given Immune couldn't act as a Taunt— the only reason for it to be used was if you stockpiled buff cards like Power Overwhelming and used them all on one turn after silencing this minion. Statline changed from a 1/3 to a 1/5. The effect has been altered to a nigh-uninterruptible Violet Illusionist for when you wish to preserve your life total when using Life Tap. Synergies with Sacrificial Pact.

Unending Resolve: The original card gave you Armor, which doesn't really fit for Warlock (apart perhaps from Hero Cards), but also discarded two cards for that, making it objectively worse than double Iron Hide. The new effect is comparable to Drain Soul and Soulfire. It may seem worse than Soulfire for discarding an extra card for one extra mana, but it does provide Lifesteal. Fits Warlock more.

Eye of Kilrogg: At 2 mana this card didn't do much anyway, so bringing it down to Blood Imp levels seems reasonable, given that it lacks the Demon tag.

Soul Harvest: Can't have Drain Soul anymore now that Drain Soul exists. This card is powercreep on the original, but the original was extremely slow and didn't do anything on its own for 3 mana. Similar to Bane of Doom and Mortal Coil, but the difference is that it's when it dies, rather than if it dies.

Soul Shard: The original version was too complicated and situational, and drawing it when it was shuffled into your deck made it a dead draw. The new version helps a Zoo deck to empty a higher-tempo hand and then use their myriad card draw techniques to refill.

Eradication: Wording fiddled with to reflect Ghastly Conjuror, and Cost changed to reflect what Corrupting Mist is worth. Wording it like Corrupting Mist is bad though, because Corrupting Mist really should have just been worded like Lucifron.

Wrath Hound: As a 3/5 for 5 that dealt two split damage, this was pretty overcosted. As a 4/6 for 5, it has more survivability and evades Priest hard removal.

Malefic Grasp and Xavian Gladiator: When Dark Bargain was released I was robbed of the name for the former, and the art for the latter. As such I had to search for new names and new art. Malefic Grasp costs 1 extra mana for the un-interactive effect, but reduces the damage dealt from 5 to 4. Xavian Gladiator was Xavian Spellcaster— the original was a 2 mana 0/3 that summoned one, whereas this is a 3 mana 1/2 that summons two. Good in token and zoo decks, I think.

Dreadful Dreadsteed: When Dreadsteed was released, the old card couldn't exist anymore. Thus, adjective added. This card is a reversal of Dreadsteed in a sense, because instead of a 4 mana 1/1 it's a 1 mana 4/4. Now that OG Dreadsteed is getting nerfed, this one feels like it should be better. This card really shines when you can buff it up and get in enough favorable trades to gain board control. It has +1/+2 on Flame Imp with the downside that it deals 5 extra damage to you.

Dark Regeneration: Since Binding Heal and Flash Heal, the effect of heals in healing classes makes a card like this overcosted at 3 mana. Thus, down to 1. 8 Health over 4 turns, mitigates Life Tap damage for that long.

Nether Ray: This, I think, is the card that was lost from the OP. The original card explanation let me figure out what it did, but I think the original one only figured Twisting Nether specifically. By 'directly destroyed' I mean Crush, Mulch, Naturalize, Assassinate, Twisting Nether, and DOOM! as examples.

In the Dark: The original version was way too slow, given Cabalist's Tome is of similar power level. I've decided to bold Void as an easier way to specify what demons (specifically demons) are available. Those available in Wild would be: Voidling, Voidwalker Voidlord, Voidcaller, Void Crusher, Void Terror, and Void Giant. This makes the pool of available targets much more diverse than the original.

Voidlord: Wording changed to reflect the mechanic, good for targeting Voidcaller to pull out a Doomguard. Stats changed from 4/6 to 6/6 as it's pretty balanced anyway.

Void Giant: Wording changed to reflect the mechanic. Now is okay as a giant because Snowfury Giant exists.

Xavius: I don't know why I didn't indicate that Dirk of the Beast should've been a token, but it obviously should've been. The old version included Xavius as a target of his own buff, which immediately made him a 7 mana 8/8 taunt. No longer. The effect on this one is more comparable to Mal'Ganis, instead of immunity it grants a 3/3 mind control effect and a greater buff on a more limited pool of cards.

Hakkar the Houndmaster: As a 6 mana 4/4, the start of turn effect was too easily countered. Now he has immediate board impact with two 1/4 Demons with "Can't be targeted by spells or Hero Powers. Spell Damage +1."

Soulstone: Simply changed to get the legendary dragon on the spell card. Effect otherwise identical.

Cataclysm: One of the things about Soulstone is that I had listed it as 'the only Warlock secret, so you know what it is'. Well that sucks, because what's the point of it being a secret then. The intent of these new secrets was to counter specific decks and to change things in a pretty major way if you're behind— this one acts as an isolated Twisting Nether on your opponent's board, but it happens twice, in case there are any Deathrattle minions that summon any more minions. Also to send a message.

Shadowfury: Really mess with your opponent's deck now we've got Gnomeferatu. Lull your opponent into a false sense of board control and then destroy a bunch of their good cards when they try to use their full board to trade with your big minions.

Fatal Echoes: This one is a bit of a meme. Basically discourages extended BM and things like putting Blessed Champion on Tirion Fordring to kill you, as it will force your opponent into a draw (that is unless you have Soulstone up, as that will trigger before this does. The other 'fatal damage' secret will also trigger this).

Stolen Power: Also a bit of a meme, specifically countering Exodia Mage and Miracle Rogue. Also very useful if your opponent gets greedy with casting spells (RIP Mage).