Tranquilizer is far and away the strongest derez effect in the game as of System Gateway. It costs two creds to install but takes two turns to 'charge' its derez, effect subject to purging. Support such as Cookbook, Hivemind, and Simulchip can mitigate its charge-up time to the point that the runner can, after buildup, instantly derez ice, and Tranq's timing means that even without support the Corp will need to purge every other turn to avoid a derez. This is pretty dang strong, but what really sets Tranquilizer apart from other derez effects is its ability to use its effect without ever interacting with the Corp. Most other derez effects require previous interactions in the form of runs to utilize their effects. Those that don't, have either a prohibitive cost or caveat associated with their effects. Tranquilizer has neither of these limitations, allowing for some truly disgusting lategame lockdowns such as threatening of 3 consecutive, instant derezzes, anywhere on the board while also allowing for powerful value plays in the early to midgame.

I suggest you try Tranquilizer out.

I can write a long write-up expounding about how analogous this is as an econ option compared to SSL or how this is just a better PriReq and the merits thereof, but instead I'm just gonna tell you to play this with the mafia Corp for the lore. Yes, it's actually incredibly potent being able to rez 10 and 7 cost ice for cheaper than free (That oughtta show em. Ah, there's my money. Hah? SSL banned? Fuggedaboutit!). Yes, even if you lose the element of surprise in the process (Whatcha lookin at, punk?).

Yes, overall it's pretty good and can fill in that space that SSL left in certain decks, but who cares about the little stuff? I added it in for the flavor. It being good was just a side effect.

"Now come on, Tony. Let's Send em' runners a Message."'

The single biggest reason why I dislike Boomerang (among many reasons to dislike it) is that it breaks Crim design philosophy. Crims, you see, are Criminals (big shocker there). Their stated goal for why they run is money and their most prominent cards embody this. Paragon (and its more broken predecessor, Desperado) pay you for running. Inside Job and Spear Phishing show how Crims prefer to evade their problems rather than waste money confronting them. Finally, Crims are, well, criminals. They steal stuff. They are especially good at punching Corps in the nose and keeping them down.

Crims however don't confront stuff all that well. They're not really supposed to, you see. Their Fracters are either good but conditional, okay, or laughably bad and outdated (meaning they are in real danger of being locked out) and their Decoders are either great but expensive or just okay. Crims splurge on Killers but only because it's the breaker type that prevents their toys from breaking the most. All this, of course, ignores Aumakua, but even that anomaly is run-dependent and thus somewhat forgiven. Simply put, Crims, more than any other faction, do not wish to overstay their welcome.

Crims lack longevity, basically. That's reinforced by their pick of the color chart as well. They're supposed to be the faction with powerful Events and Resources but little in-faction recursion, and the wisdom of that design decision really shows in Boomerang. Boomerang's self-recursion ability propels it from good to just plain obnoxious. Crims are the Runner faction that emphasize the early game, with a playstyle defined by tempo, control, and resource denial. Crims are supposed to hit fast and hard, getting away with anything, but needing help to reach their goals honestly.

Boomerang breaks that mold entirely. Its recursion is infinite, allowing for cheap, endless, strength-ignoring breaking, fodder for endless installs, and its trash ability allows for endless profits. Boomerang on its own defines Crim endgame strategy in that the Crim endgame is simply 'infinite Boomerangs.' 'Infinite Boomerangs' is, in fact, so good and reliable an endgame strategy that other factions import it in. The faction that's supposed to have the weakest endgame is now having their endgame strategy imported by other factions...

Let's hope that easy, infinite self-recursion isn't something pursued in the future. We already have two cards like that, both of them in Crim. One of them is Boomerang and the other one is banned. Note that the banned card has much more stringent recursion conditions than Boomerang.

Fun fact: did you know that a fully loaded Akhet can act as a wincon? Yeah, if you stuff a City Works Project, a trap, or, hell, a Bio Vault behind two of them, it can clicklessly charge them up while also giving you creds to use (like, say, for traps). It's great fun.

Formicary is a good Weyland sentry. It's no Archer, Surveyor, or Colossus, but it is a cheap sentry you can slap down on your remote and then have magically defend your centrals when you need it to. Its sub isn't the greatest in the world, it lets the Runner pick their poison after all, and its rez-to-break ratio isn't all that great either, but it's effect is punishing enough that Runners would rather just end the run if they facecheck it and its effect practically begs the Runner to facecheck it when they least expect it to. I think 2 creds for it is a steal, honestly. Also, Formicary was the central part of a hilariously degenerate combo that led to the first banned NISEI card. Since it had the exact same trigger as Cayambe Grid you could choose to let Cayambe fire first, then Formicary, then Cayambe again after the runner breaks the Formicary, then any other Formicary you had laying around, then Cayambe again, and so on. It was not unusual to force the runner to pay 30+ creds on a single run. That was a wild time.