I think this card is very good, defiantly deck defining. Giving you 4 of any card seems really good; having four Unearthed raptors for a Deathrattle deck or three Edward VanCleffs for a combo deck is insane.
I think the best combo is simply 2 shadowcasters, brann, and 1 shadow step. Emperor thaurisson is not required but allows you to start the combo earlier. So the basic combo as I'll call it is a 4 card combo, and nothing requires an emperor tick.
The basic combo takes place over 2 turns and gives you 2 mini branns and 5 mini shadowcasters. Due to the sheer number of shadowcasters that exist I will call them shadowcaster 1,2,3, and mini shadowcaster 1,2,3, and so on. Hence forth I will also abbreviate shadowcaster as SC, giving us a notation of SC1, SC2, SC3. Also, we will call a mini shadowcaster mSC, so our collection of mini shadowcasters will start with mSC1 and build up over the course of the combo. If you took some math classes in college this will be easy to follow. You have 10 mana for each turn.
You play SC1, then copy it with SC2 giving you mSC1, you then shadowstep one of them giving you SC3, which costs 3 mana. You now have mSC1 and SC3 (discounted mana cost of 3).
The following turn, you play brann, copy it with SC3, and copy SC3 using mSC1 giving you mSC3, mSC4, and 2 mini branns. Using mSC3 gives you mSC5 and mSC6, using mSC4 gives you mSC7 and mSC8, using mSC5 gives you mSC9 and mSC10. You end the turn with 2 mini branns and mSC(6-10). So that is five mini shadowcasters. Note that the comboends up producing a lot of incidental minions on the field that you can use to trade up. You are hoping to trade them all or get your board wiped. Otherwise you just chip away at their armor or health with them until you can get more board space.
There are different things you can do with the combo. But just to take an example and roll with it we will do the malygos run through.
After the above 2 turns, we are at the 1st turn of what I'll call the malygos sequence. You play malygos and mSC6, giving you a mini malygos in hand, at the cost of using mSC6, leaving you with 4 mini shadowcasters in hand.
Because the next step is limited by board space it ends up not mattering at all if the original malygos lives or dies, but you are hoping to trade in the mSC6, you lose out on 5 spell power if you cant get rid of it. So this next turn will rely on mini malygoses, which we will denote as mM1,mM2, and so on. You play mM1, play the second mini brann,use mSC7 to give you mM2 and mM3, and so on.
Spending 8 mana on this turn gets you 4 mini malygoses, a mini brann, and 2 mini shadowcasters out on the field, leaving you with 20 spell power and 3 mana to use. You can for example sinister strike + evisc + prep evisc to get 71 damage, or just sinister strike + evisc for 47 damage. If the warrior has over 71 armor/health, you can delay the comboby spending this turn to further duplicate mini malygoses, you just have to make sure that you use the last mini shadowcaster to duplicate for more shadowcasters. All of the incidental 1/1s will chip down his armor or trade up with his board. If he removes all of them with a whirlwind effect, or has a minion that you can trade them all into, you reset the board and can play 7 malygoses, giving you 35 spell power, the max possible. Just achieving this astonishing max number of spell power is an achievement in itself so be proud at this point. I will make an attempt to be the first person to do it and show it off on youtube. With 35 spell power and 3 mana and some spells that deal damage the game is yours for the taking. Sinister strike + eviscerate deals 77, sinister strike + evisc + prep evisc deals 116. If you stop at 6 malygoses you have 4 mana, allowing a double sinister strike + evisc for 100 damage.
The only thing I haven't done yet is do a hand size check, it is important to know how much the hand size fluctuates through the turns. I'll work on that next. You have to track all of the cards used with the cards generated through each turn and determine the max number of cards you can start with in hand before proceeding with the combo. You will have to use enough cards prior to going off for this to work.
The basic combo uses 4 cards to generate 7 cards. If you count the draw for each turn you have 9 cards, allowing 1 card to be saved before starting the combo. It is not necessary to have 5 mini shadowcasters, so you could intentionally burn 1 or 2 of them. For the malygos sequence, if we burn 2 of them we can save a malygos and 2 damage spells, or malygos, prep, and 1 damaging spell. You can burn 3 of the shadow casters with intent to later duplicate them as needed to preserve malygos and 2 damage spells + prep, or 3 damage spells. So it seems that we can work with the hand size for this and manipulate it as needed. Note that you will never be able to draw from the deck again so you have to have everything you need before going off. Every draw will be burned, you are just trying to save damaging spells and fill the rest of your hand slots with generated mini minions for the rest of the game.
Also, this confirms that Rogue will never ever be getting a good cheap drop ever again, if past trends mean anything. Thanks Blizzard.
If they use this as an excuse for not giving Rogue good early game minions in the future (or fair as they're doing), then they'd better delete the class. It's the same argument for every Rogue card. If that's the mentality, then Druid shouldnt get strong/late game minions because it has buff cards, Mage shouldnt have minions with spell synergy because they have the strongest spells and Paladin shouldnt have dude synergy cards because they can abuse it with their hero power.
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'There is nothing more deceptive than an obvious fact'
not totally correct... The buffs on C'thun will still apply on the 1/1 copy, because they don't just buff the 1 C'thun in your deck... It will apply to all Copies
Consider the C'thun buffs more as Playerbuffs than Minionbuffs
anyways its still useless to use her Battlecry on C'thun because if u already have a C'thun on steroids on board, u probably already won the game...
In C'thun decks its more favourable to get 1/1 Copies of Dark Iron Skulker for board control or C'thun buffers...
It will apply to copies, if it exists. If you already copy your C'thun, it will copy it into a 1/1. So in order to take effect for it again, you'll have to re-buff it. The buffs are not automatically applied. Otherwise, it will be very broken.
Not sure why I haven't seen more folks consider Nerubian Egg as a good target for this Shadowcaster. I know it's fun to dream up big, flashy combos, but ones with high-cost, high-impact minions that require your opponent to leave up a Malygos or something don't seem practical. The actual practical scenarios are going to be with smaller minion that actually stand a chance of surviving a turn for normally being so innocuous and/or that can actually easily be played the same turn. In that regard, I think Nerubian Egg is a fantastic, practical target because 1/1 is actually a buff to its default stats. With an actual Attack of 1, you don't need to buff it for it to be able to attack, and with a Health of 0 you'll get that 4/4 you actually want out more easily. Though maybe folks aren't paying much attention to Wild. XD