It probably is serious.

You’d probably be better off hoping for a true successor to Sludge Belcher, Refreshment Vender, AND Antique Healbot. Those three cards are at least two thirds of the reason why Control Rogue was ever possible. It was never because of the weapons rogue has one Blade Flurry was nerfed.

Vanish is six mana and is the only board clearing spell available to the class
Onyx Spell stone is five mana and requires deathrattle minions to be played to become even almost playable
Assassinate is five mana and only kills one minion
Vilespine needs to be comboed to kill a minion and costs five mana by itself
Valeera the Hollow costs nine mana and can only save you for one turn
There are no good lifesteal cards for Rogue and as such Rogue has no good healing options
The weapons Rogue has at its disposal are not very good compared to Paladin, Shaman, or Warrior.
Kingsbane requires an entire deck built around it to be viable
You can only play two Saps and two Preparations
The draw Rogue has is limited to Auctioneer, which needs a deck built around him, or Evlen Minstrel, which can only draw minions, for the most part

Those are all the reasons why control Rogue has not been possible since the rotation of cards like Antique Healbot, Dark Iron Skulker, Refreshment Vendor, Azure Drake, and Sludge Belcher .

Yes. A card that cost four mana, doesn’t affect the board when played, and only makes match-ups that are already good for value based rogue decks even better is overpowered.

However, this card would not help out in the types of match-ups Miracle Rogue has historically struggled against. It will just make already good match-ups even better.

The value is insane, but unless the format slows down even further than it already has, the absolutely zero tempo gained through playing this card will make it unplayable outside of the most value oriented Rogue decks.
Yes, the tempo can easily be regained when you top deck the cost reduced cards, but the upfront cost of four mana’s worth of tempo to get nothing immediately will be far, far too much for just about deck outside of a control match-up.

The kind of decks this card would be a great against are already decks Miracle Rogue would tend to win out against. This does nothing to compensate for the weakness of Miracle decks generally, aggressive decks, and giving up four mana’s worth of tempo in the midgame against an aggressive deck like Odd Rogue or most Hunter decks is basically the equivalent of pressing the concede button unless you topdeck a twisting nether, vanish, or another similar board clearing card.

One would play this card in either a Miracle Rogue or Pick Pocket/Burgle/Thief Rogue.

This is an auto include for a Burgle Rogue without question since there is no card that generates as many class cards as cheaply as this does. Plus, that deck is fine with gaining gradual value over time.

However, playing this in a Miracle Rogue deck would mean this is the only card in the deck that does not and cannot generate any sort of tempo when it is played. The only other card that could be said to generate little to no tempo would be Elven Minstrel since it is a four mana 3/2 but it is a better arcane intellect, making it at least five mana in value.
Miracle Rogue also already has really good match-ups against value oriented and combo based decks like Even Warlock, Taunt Druid, and Sudderwock Shaman, making this a win more card against those at best. What the deck needs is better anti-aggro tools rather than a card that improves a match-up that is already tilted in their favor.

Getting a one mana Tirion Fordring would be great and would probably win most games that happens in, but the upfront cost of getting to that is going to end up being too great.

Perhaps, but if it does become a common practice in the deck, you are just asking people to play an extra piece of AOE removal.

This card is four mana do nothing, and when I see this, I see this set’s version of Cataclysm from Kobolds and Catacombs. It might make the deck finally work to a really forced extent.

Sure a value oriented Rogue probably plays enough draw to make this worth it in the long run, but that’s the thing. It has to be had in the long run. Burgle Rogue is a deck that get’s slaughtered by anything that can kill it before it can create value from the myriad of cards it generates and even its best match-ups are against decks without much of a win condition to begin with.

I also stand by the fact that the best counter to a Burgle Rogue would be any other Rogue deck. This card does not help resolve that fact nor does it do anything for the decks inherent weakness against anything faster than Big Spell Mage.

It’s exiting, it’s big, and it will help the deck win out against control and value oriented decks, but it’s far from absolutely game breaking.

There are a quite a few bad legendaries in Un’Goro, probably about as many good as bad, at least for a Control Warrior, so the quality on the Un’Goro isn’t always going to be higher than three random mechs. Additionally, the cards that can be gained though Omega Assembly can be gained instantly rather than having to be waited on until the Un’Goro pack ends up in your hand.
Either way, the main idea of the Un’Goro pack and this card is that both are a cheap source of late game value that, when played, will probably edge the game in your favor.

Alright then

Perhaps, but that will depend on what happens when you give a minion with Charge Rush. If I had to guess, Rush’s limitations on what a minion can do will probably override the freedom of Charge.

It’s kinda cool to see a neutral version of Despicable Dreadlord. I understand that this one is worse in all aspects, but there are classes that this would be perfectly acceptable in since they might not be able to deal with wide boards very effectively. Plus, as long as token decks remain popular in Standard and since this can be stuck onto a minion, Mech decks will at least consider playing this.

I would hardly call this card over powered. It’s a nine cost legendary spell. You would expect it to have a big effect, and it does, but unlike Shudderwock and Master Oakheart currently, it can’t outright win games. Your opponent will have at least one turn to respond to this after their opponent’s minions have attacked. Sure they have the same amount of time to respond to Oakheart, but Oakheart functionally summons up to five minions, one of which is usually Hadronox.

If this were in the format we are in currently, it wouldn’t make Recruit Warrior that much better. It would allow them to dump the handful of big cards they’ve gathered over the course of the game, but I don’t think it would shift too many winrates outside of Shudderwock Shaman.

The Boomship will be a good card across slower warrior archetypes, especially Recruit Warrior. I don’t really see it being played in a Mech Warrior since the Dr. Boom hero card already give mechs rush and there’s enough small minions in that deck that might still be in one’s hand turn 9 that playing this seems largely unnecessary.
It is an exciting card, but if the format does not speed up a lot, this card will rarely win games outright since most of the slower classes should have an answer to this card and the minions it summons can’t deal damage to heroes. However, against aggressive and midrange decks, the kinds of decks I hope Boomsday format shifts to, this will pretty much be a finisher with a slight delay.

The whole point of the Big archetype is to cheat out expensive cards as early as possible. While this is a powerful effect, it comes down at a point where most classes will have either wanted to win already and their opponent has probably already drained them of resources or have answers to such a card.

While Warrior does have some of the best control tools in the game, it still struggles against anything else remotely control based. This will probably be a part of a competitive Warrior deck, but a nine cost legendary spell that can’t really win you the game the turn it’s played will only ever be a part of the reason why the deck is good, but not the whole of the reason.

Why would a seven mana 5/5 that can eventually deal eight face damage be the new Dr. Boom? It’s not exactly a great tempo play for a midrange decks, and aggressive decks can just ignore it unless forced to deal with them with the application of some Magnetic cards.

Odd Hunter also wants to end the game as soon as possible. If turn seven comes around for that deck and you don’t at least deal near lethal damage that turn and instead spend it playing a bunch of set up for the next turn, you’re probably going to lose.

That’s not to say the card isn’t good. It’s just not going to be an aggressive powerhouse. If it were, it would either be five instead of seven mana with an appropriate reduction in stats or the damage it can deal would faster.

What one mana 1/3 is Warrior playing now that this pushes out of relevance?

The class identity of Shaman has been the most consistently muddled. This is another example of that.

Eureka! closely resembles Gather your Party from Kobolds and Catacombs. While Recruit Warrior has been somewhat successful at least on a causal level, the typically aggressive manner in which Shamans conduct themselves wouldn’t really want to cheat out a big minion. Even during the reign of Midrange Shaman during the second half of 2016, the deck only played on minion they could cheat out with it: Ali’kir. I mean you could get a pair of Ali’kirs with it, but I don’t think that by itself makes that card worth playing.

There will need to be a couple big minions Shamans really want to cheat out for this to be good.