There are two different (and non-exclusive) ways of looking at Cyberdex Sandbox.

The first is as a piece of tech hedging against virus decks. It gives you a free purge on score and repays the credit cost of the score (but not the clicks!), and it makes future purges forced by threats such as Medium less of an economic setback by compensating you with 4. Compared to Cyberdex Virus Suite, the existing neutral standard for virus hate, you get a more reliable and repeatable upgraded purge ability, and your tech card takes up an agenda slot, which is generally better to make sure you get enough space for plenty of ICE, economy, and other utility cards. While Virus Suite charges you 3 and a for a manual purge, it is also an ambush which can shut off Archives from Datasucker or Aumakua counter farming. The fact that you can purge with a pre-installed CVS also makes it a shoe-in against Clot if that card is likely to hamper your fast advance plans.

The second is as an economy agenda that immediately somewhat compensates you for scoring it, and then offers a slight improvement over spending on basic "take a credit" actions. This isn't fantastic, but I think it does compare favourably to the now-rotated Gila Hands Arcology; the immediate buy-back of 4 makes scoring much less painful, although it probably takes two or three more manual purges to actually be economical. Not great though when Corporate Sales Team pays out 10 without demanding any additional clicks, and it pays that out relatively quickly too. If you just want cash, Corporate Sales Team is virtually always better, and it is even the same advancement requirement to points ratio.

So, if you're going to play Cyberdex Sandbox, you have to want the purge and not just the credits. If you're playing a lot of fast advance, Cyberdex Virus Suite is still going to be your first choice of virus hate, but Cyberdex Sandbox can carry tempo and glacier decks further by offering repeated economical purges. Of course, if Freedom Khumalo: Crypto-Anarchist somehow becomes the runner meta you could play both, and if you don't need virus hate at all, then you don't need either.

One final note is that Cyberdex Sandbox, over all other virus hate, actually self-synergises and rewards you for purging through other card effects, such as Macrophage and Reverse Infection. You score a second Sandox and now you get 8 and you can spend for 8 again whenever you want! Maybe you do want to play both Cyberdex Sandbox and CVS after all! While this sounds like a huge deal and a powerful way of playing this card, I actually think this is at best a fun gimmick, and at worst an outright trap. It is not easy for most corp decks to stomach multiple 2/4 agendas, and there are plenty of others you can score twice (like Nisei MK II or over-advanced Project Atlas) that can straight up win the game and don't demand going all-in on virus hate that will be largely dead in some matchups or until you score your vulnerable 2/4. All Nisei MK II needs to support it is some good taxing ice and a functional economy, and unlike Reverse Infection, you were probably playing those anyway.

Kasi String is a really bizarre card. You have to make a successful run on a remote server and access cards without stealing an agenda. This is something that just won't happen four times over an entire game against most corporation decks, let alone happening four times over four different turns fast enough to "score" Kasi String should you draw it late in a game. But access to points in the runner card pool is pretty rare and always conditional, and in the right matchup Kasi String does compare favorably to Notoriety.

The matchup where you will regularly access remote servers without stealing agendas is against asset spam. Decks for IDs like Controlling the Message and at least some Asa Group and Replicating Perfection decks will leverage their identities to protect lots of assets that generate a strong drip economy, or else force you to burn your precious credits trashing all their stuff. Against these decks, Kasi String provides a good reward for running on all those agenda-less servers in the form of additional points. I think it is pretty pheasable to slot 2x Kasi String (or maybe 1x if you can dig for it with Gachapon) and expect to score that additional point in these matchups, accepting that your tech card will be dead against more conventional Corporations.

Just like Notoriety, Kasi String might let you close out a close game where you've run aggressively and stolen early agendas before the corp can fully establish their economy and safely score. This is certainly desirable against asset spam, as most runner decks are a bit faster and aggressive than they are, but that gap gets much closer when you're having to tread carefully around SEA Source or Hard-Hitting News. Given the existence of cards that can punish you so harshly for falling behind on credits, you are probably better off fighting asset spam on the same economic axis and playing a card that helps you trash their assets, such as Scrubber or Miss Bones, and this is definitely true if your runner deck also needs time to get its own drip economy going. You just can't run and trash an asset every single turn against these decks without heavy economic support - they're built to make that as difficult as possible - and so Kasi String ends up having to play second fiddle to cards like Scrubber. You could play both kinds of cards, and Scrubber definitely supports Kasi String well, but this is only viable against a meta with a lot of asset spam.

Still, I find myself appreciating the design of this card a lot. Netrunner has always had a back and forth between corp and runner with "silver bullet" cards that really challenge particular decks and shore up weak matchups, and Kasi String is a really interesting and novel card of this type. Maybe there's a home for it in the future, although hopefully not in a context with an excess of prison-style asset based decks.

Jua is a cheap and unassuming sentry with the possibility to really bite against the right deck. Even when broken by some of the most efficient Killers that match up well against it (Mimic, Na'Not'k with two or more ice, and Bukhgalter on the first break) it'll tax 1, which is perfectly respectable for ice that cost only 2 to rez. For less conventional breaking, 3 strength is passable for resisting Chisel and Aumakua, but of course the single subroutine leaves the possibiltiy of being broken by Boomerang.

As for letting that subroutine fire, that depends wholly on the runner's board. Obviously against a blank rig Jua's subroutine is effectively blank too, so it's not a great way to defend a server on the very first turn, but given its a cheap porous NBN sentry that was always going to be true. The subroutine can in some scenarios backfire, forcing you to offer the runner to topdeck a spent virus such as Imp or Pelangi, but thankfully the tempo loss of redrawing and replaying something like an almost empty Earthrise Hotel or Daily Casts is substantial enough to not make that a real worry. Also there's only so many times most runners can run with only one card they don't want you to bounce installed, so I kind of doubt this downside will come up often in play. Typically, firing Jua's subroutine is going to be a steep tax of tempo and could even remove cards the runner needed for the remainder of the run, forcing a jack out.

On top of that though we have the wacky encounter effect which could be useless or severely punishing depending on the matchup. Anarchs and Shapers tend to be the factions with the most effects encouraging them to install cards during a run, which can make an unrezzed Jua a nasty surprise when they were expecting to have access to the Flashpoint conspiracy breakers or to use Self-modifying Code or Simulchip to protect themself from dangerous ice. Hilariously, even if your opponent does get MKUltra onto the board its 3 to break Jua, making this card a brutal pick against self-milling Anarch decks. The effect lasts for the remainder of the turn too, so it's not like they can jack out after Jua, install a sentry from grip, and then run again. Against Criminal there's not much you'll shut down in this manner, although I did get to experience Jua being effective at closing off a server being farmed for Crowdfunding runs while that silly card was still legal.

Honestly with Self-modifying Code continuing to define the flow of runs in this beautiful game, I'm surprised we aren't seeing more of Jua. Anarchs may have lost their precious Inject making the conspiracy breakers a bit weaker, but many players are making up for that by importing SMC anyway, so go figure. I suppose it is somewhat getting muscled out by the other cheap NBN ice that we've all gotten used to treating as staples.

Random trivia: Masvingo is the only Netrunner card to date that uses neopronouns in its flavour text.

Masvingo joins the long history of advanceable Weyland ice that gets better the more advancement counters you pile onto it. Alone, with 3 strength and 1 ETR subroutine, it sits neatly between Ice Wall and Fire Wall as an afforable gearcheck that typically taxes more than 1 - exactly like Wall of Static. It is particularly taxing for a handful of breakers that boost awkwardly or break multiple subroutines at once, such as Demara and GS Sherman M3.

Unlike its predecessors, Mavingo gains additional ETR subroutines with advacement counters rather than gaining strength. Against the gold standard Corroder this is essentially equivalent, but for other breakers this is mixed news. Paperclip only starts paying more than 2 with at least 3 advancement counters, whereas the aforementioned Sherman will pay 4 for both 1 and 20 advancement counters. On the bright side, you can lock out Quetzal with a second counter, Boomerang with a third, and Spike with a fourth. Against the ever-popular Aumakua whether you prefer gaining strength versus subroutines depends on whether you want to lock the runner out or tax hir.

Masvingo hasn't really seen a great deal of love outside of Builder of Nations - where it shines from turning on your ID by having its first counter free - but with the newly released Akhet and Wall to Wall breathing new life into advanceable ice by charging them efficiently, we might be seeing it more often. I think all but the fastest Weyland decks will prefer Masvingo to Ice Wall because those counters start mattering sooner against most fracters (Corroder and Gauss). As for Fire Wall, I think these days if you're paying more than 4 for your ice it should probably come with a facecheck penalty and prevent Turning Wheel counter farming. Masvingo compares favourably to the old competition, and is probably your go-to dump for excess advancement counters.

Engram Flush, like Slot Machine, is a cheap to rez but taxing to break code gate with unassuming subroutines. Slot Machine is great, and I'll compare Engram Flush to it to get some sense of how good this new code gate is. Incidentally, both reveal runner cards, and thus can give Hyoubu Institute a credit.

2 for a strength 5 code gate with two subroutines is a fantastic deal if the runner breaks those subroutines. If they don't, they're liable to lose a card or two provided you have a read or knowledge on what they're holding, which you're likely to have in Hyoubu or Chronos Protocol. You can hunt down any I've Had Worse the runner might be holding for your damaging ice by naming Event, and in general the ability to pluck chosen cards out of the runner's grip is already what Chronos Protocol decks are going for.

Both Engram Flush and Slot Machine are somewhat liable to misfire and won't always be as powerful. In Slot Machine's case, it depends on the top cards of the runner's stack, but at minimum you will cost the runner 3 even if their stack is empty or they blank its encounter effect. Engram Flush on the other hand can be walked through with an empty grip, although that's probably a bad idea against Jinteki. Engram Flush will also do almost nothing against Hunting Grounds or if you just name the wrong type with the encounter effect, which the runner will know before they choose to break or not.

I think you probably have to really be taking advantage having existing knowledge of the runner's grip to make Engram Flush good enough. It's less reliable than Slot Machine, although it is a whole credit cheaper which is a big deal at such a low cost. My prediction is that this card is good enough for Hyoubu Institute and Chronos Protocol, and maybe Harishchandra Ent. at a push, but its going to be a tough sell for any other corp.