The ever continuing quest to make a Negative deck more stable continues. Another test deck, but this is a mix of Negative with Cerebro 3 that spawned from looking at 0 cost cards that would be good to fetch with Jane. After playing a few games using Jane, I streamlined the deck down to this. What I was finding was that just stuffing 0 cost cards in with Jane is too inconsistent to my liking. Aside from the fact that playing Psylocke into Negative is uncommon, you just end up with too many cards in your hand that Jane just doesn't end up fetching any cards, if at all. It also made Bast awkward to play when Jane is in hand at the same time, but you don't have Negative on hand.
This revision settles on playing Negative with a side of Cerebro as an alternative Win-con. It's not perfect by any means, but it does let you keep playing even if you don't draw Psylocke -> Negative. Flip side, the payoff for getting Negative out can still be quite huge. There are lots of "Mandatory" cards that I'd consider making up this deck, so you have to be pretty far along Pool 3 before trying it out. You can of course try playing without one of the mandatory cards listed, but it will probably be even shakier so I don't recommend it.
Most of the Essential cards are pretty self explanatory. You run Psylocke -> Negative to then invert your deck and basically play really powerful reversed cards to win. On the Cerebro side, you have the name-sake card along with Bast and Valkyrie - two crucial pieces to 3 power-wash your deck and field. The rest of the choices are supporting cards which you can sub around but the ones I chose for the deck help both play-lines.
ADAM WARLOCK - A large part of this deck relies on seeing what pieces you get to determine which Win-con to build towards. Warlock's draw effect is huge for that. Bast-> Warlock is pretty staple in terms of using Warlock in general. Helps with overall consistency of the deck.
CAGE - Playing Cerebro without Luke is pretty painful. There are tons of locations that adjust your power downwards which would be a very detrimental. Cage basically laughs at that and lets you use those spaces pretty freely. I recommend playing Cage late into the match to reduce the chances of getting Rogue'd or Enchantress'd. He has a big play window, so don't feel like you have to play him immediately. Shadow King is an alterative to Cage but the extra +1 cost and lack of benefit from Negative's inversion means he's a sideboard for me.
MYSTIQUE - Anytime you have some great ongoing effects, Mystique is always a top tier choice. No exceptions here. She does have less targets which is the one thing to watch for. Still highly recommended.
ABSORBING MAN - Absorbing Man has one main use here but it's a big one: he lets you duplicate Valkyrie's effect. Valkyrie is really strong because she forces power of all cards played into a lane to 3. Meaning unless you have a way to break parity, it is impossible to win the lane barring out muscling your opponent via the number of cards. We, of course, have a couple of ways of doing so. Your opponent might not. And even if they do, maybe not played into two lanes, which Absorbing Man lets you do. He can also combo similarly with Shadow King to turn all the cards you played back to base power - useful if facing locations that boost power up.
IRON MAN - Pretty staple in Negative decks. Offers another way to break parity if you don't draw Cerebro. Also great when hit with Bast. Probably your 2nd "Big gun" so to speak for massive power swings.
MAGIK - In the world of Negative, you need an enabler and then a draw engine once your cards are Negative. We already have Warlock but Warlock can fail since you can lose the lane. Magik is guaranteed +1 draw and if you get inverted cards, you can burst power way more scarily than an opponent. Also bypasses Wave-locks which helps. I find Magik pretty mediocre otherwise, but Negative is one of the few decks that greatly benefits with an extra turn.
VALKYRIE - Already discussed somewhat under Absorbing Man, but Valkyrie is an amazing card and your primary "Big gun". If your opponent can't break parity, you will basically win the lane once you pair her with another one of your Ongoing cards. You do have to be careful of the opponent's Ongoing effects though - specifically Cage will eat her Reveal effect for free since he prevents the Power drop and will gladly take the boost up to 3 in her lane.
ZOLA - You will notice this deck doesn't have much reach. Zola serves to bypass that somewhat, and can duplicate your Valkyrie or Iron Man. His 0 power isn't great, but you can work around that.
Often times you lines of play will be to play Bast once she has a good number of targets. Using Bast with Cerebro, IM and Mystique in hand is kind of the nuts of draws because it turns your Mystique and Cerebro into +7s on their own. If they were hit with Negative, it is the same deal except now it is free. If you don't have a good number of targets to hit, feel free to hold onto her because Bast basically has a play window from 1-5.
On 2, if you've played Bast and have Adam in hand, playing Adam for the extra Draws is probably the right move most of the time. If you have Psylocke and Negative though, I'd play Psylocke into Negative on 3 instead. If you just have Psylocke or Bast didn't hit Adam, then Turn 2 is kind of gamble. I'd still play Psylocke since it is possible to top-deck Negative, but you have a bit more choice here.
On 3, Negative if you played Psylocke previously. Otherwise, playing Bast here is good if you haven't already since she will basically hit 5 cards. You can also Psylocke this turn so you can play a 5 cost earlier. Playing Cerebro early is an option, but it depends on your hand. One of Cerebro's advantages is that it is not a deck with obvious lines of play so opponents don't tend to suspect it.
On 4, natural Negative, Psylocke -> Magik or Psylocke -> Iron Man are options.
On 5, playing Magik , Valkyrie or IM depending on the situation. If you've inverted your deck, play Magik. If you haven't but have some good board presence, you can drop Valkyrie or IM, which will give your Absorbing Man and Mystique some options going into 6.
On 6, you can Zola your Valk to basically drop everything to 3 power. You can also do Cerebro into Mystique for a +4 to everything on the field. If they got hit by Bast, this can be a real tide turner because it is essentially 14 power for 6 Energy. Even better when Bast or Valk other cards - especially Iron Man.
That's the idea in a nutshell. If you get Negative and Adam going, you can pretty much draw your deck and then dump everything on Turn 6 for a big scary surprise. But if you get Negative out on 3, most people know they have a fight on their hands. And if you start getting draws, the smarter ones will likely retreat, so you're probably going to play in more disadvantageous situations than not.
On the Side Board pieces - you can sub these in pretty freely for other cards. In general, the Cerebro shell wants lower cost cards so you can put more of them down, but the Negative side wants low power. So accounting for this mix is actually quite difficult:
ROGUE - 3-1 Tech card that lets you steal an opponent's Ongoing. Great for stuff like Wong, Dinos, etc. Do be careful when stealing an ability that gives power though because it will instantly screw up your Cerebro play.
BLUE MARVEL - He's a +1 to everything which means you can break Valkyrie's parity. On top of that, he's also 3 power, 5 power reversed, which means you can end up doing Cerebro 5 with like IM by mistake. Negative lets you hand dump due to the reduction in cost, so he's actually really good here. The issue is, what exactly do you take out? I assume either Zola or Absorbing Man, but then you lose reach in the former and the chance to double up Valkryie in the latter.
BROOD - You'll ideally want Brood reversed so it becomes an effective 2-9, which can then be Cerebro'd. However, even not inverted Brood isn't terrible since the body he drops can then be Valk'd - but to truly win, you'll need to break parity and that means you should probably add Blue Marvel as well in the off chance you don't draw Cerebro
SHADOW KING - Cage will guard your cards from losing power. But Shadow King is the only thing to really bring the power back down. Valk sets everything to 3 - which is better in this case for you, but she also costs 5. A very steep work around cost. Since his cost reduction, he can now serve as tech AND to rebalance the power on your end for Cerebro. Further up side - he's an On Reveal, so he can't be stuffed by Rogue or Enchantress.
WASP - Purely for the Cerebro end. If hit by Bast, becomes an instant 0-3 or possible 0-7, which is kind of nuts for obvious reasons.
ZABU - Purely for the Negative end. An alternative to Psylocke. You're not running a bunch of 4 cost cards and the Ongoing effect is worse than Psylocke's On Reveal since it means you can't play Zabu like a sacrifice. However, reducing your Absorbing man to 3 cost means you can play him alongside Cerebro so you can do something like Valk -> Absorbing Man -> Cerebo. Basically adds more flexibility.
RHINO - Magik already exists on 5 as a real estate agent in the event of a bad location roll. However, if you want to dig more in the Cerebro side, I'll see if I can sub in Rhino. He's a 3-3, so he won't benefit off Negative, but turning a location into pure neutral can be a godsend for stuff like Throne Room. The other real estate agents have notable downsides here. SWitch is a 2-3 so becomes worse under Negative and the random location can equally screw you. Storm is 3-2, so you'd think she's a good fit...except for the fact a lot of your cards you'd want to play late, so she's an awkward fit for your curve. You'd need to play Storm later than 4 to get a net neutral effect and you'd often rather play a raw Bast'd IM or Valk. Quake is a 2-3 and is a pseudo real-estate agent. Similar issues as SWitch as a result.
That's it. Will be playing around with this, so expect this recommendation list to change with time.