Adding a review as there isn't one at the time of writing.
Isaac Liberdade is a mobile Sysop, sometimes called a "nomadic" Sysop. This means that, unlike most upgrades, Isaac can move himself around, allowing the benefits of a single, unique card to potentially affect multiple servers across multiple turns. He's one of 4 such mobile Sysops released in the Liberation Cycle, one for each Corp, alongside The Holo Man, VovĂ´ Ozetti and Adrian Seis, the collective of them bring a new mechanic to the game, something that is both refreshing and fascinating. Used correctly, protected, and moved around to where they are most needed these cards can provide incredible value.
At the end of your turn, you may move Isaac to a different server and whenever you do move him, he can place an advancement counter on an unadvanced piece of ICE, note: it does not specify that the ICE itself must be "advanceable" so even though you would gain additional value from advancing a piece of ICE which gains benefits from being advanced, you can advance other pieces of ICE, purely to allow Isaac to set himself up and give himself more targets to increase the strength of.
That being said, Isaac synergizes well with advanceable ICE, since placing an advancement counter on an advanceable piece of ICE is more valuable than placing it on a random piece of ICE and if you already have advanced ICE, Isaac can start increasing their strength immediately. Advanceable ICE is an almost uniquely Weyland mechanic (if we ignore Mestnichestvo) that has gone through multiple iterations throughout the game. Back from Lunar, we can see cards like Tyrant or Woodcutter which could be advanced and gained additional subroutines for each advancement counter, or the set of "space ICE" like Asteroid Belt or Wormhole that gets cheaper when advanced, or ICE that gained additional strength when advanced like Fire Wall or Ice Wall as well as the "7 wonders" archetype that gained special bonuses once they have at least 3 advancement counters like Hortum or Pharos. And, it's a mechanic still going strong today with two new pieces of advanceable ICE released in Liberation Tree Line and Logjam.
Pros / When to Use
Isaac is best played not only with lots of advanceable ICE but also with very large, vertical servers. The more pieces of ICE he can increase the strength of at once, the more value he can generate. In such a situation, he can be bounced back and forth between HQ and R&D or between centrals and the scoring remote, both to stack up advancement counters and to adapt in real-time to where you think you could most benefit from increasing the strength of the ICE to tax or dissuade the runner.
Cons
Unfortunately for Isaac, the metagame in the standard format does not favour glacial, the prevalence of Orca/Lobisomem Kit, K2CP Turbine/Takobi Lat and Arruaceiras Crew ICE destruction Anarchs hasn't been kind to glacial and most people seem to prefer playing assets spam R+ or kill based PE or Thule or just rushing the runner out with PD or Asa, plus whatever AgInfusion: New Miracles for a New World is doing. Building lots of big servers just isn't as actually taxing as you might think.
Beyond that he's expensive to rez and cheap to trash which is never a good combination, you have to try and keep him alive for at least a little while to get him to pay for himself, let alone turn a profit, and that can be hard when the whole point of his ability is that you want to put him on the server you think the runner is most likely to run.
Additionally, the identity you probably think you want to include him with Weyland Consortium: Built to Last, because they both like advanceable ICE, is a bit of a red herring, no pun intended because BTL likes to be the one placing the first advancement counter and so does Isaac. If you didn't already know, BTL has a weird piece of wording that essentially means you only get the credits if you advance it with the basic action, it doesn't give you credits if you "place an advancement counter" such as through Isaac, Wall to Wall or Priority Construction. This makes Isaac clunky to use in BTL at the best of times and actively anti-synergistic at the worst, where either Isaac places the first advancement counter and you miss out on the bonus credits or you place the first advancement counter and Isaac is left without anything to advance. Neither of which allows you to get the most value from Isaac or your identity. Perhaps he is better suited for some kind of glacial Nuvem SA: Law of the Land deck but most Nuvems I see are usually just trying to do some kind of kill combo with End of the Line or Punitive Counterstrike.
This is usually the part where I write a thematic review but since Isaac Liberdade seems to be a fictional character who is not based on anyone in real life and since we don't really have much lore to go off of (unlike The Holo Man for example) I'm just kinda going to spitball here. We know he's a bioroid in Brazil, which means he's freed, which means he's not property... which means he's been hired by and is voluntarily working for Weyland, one of the megacorporations who are secretly trying to enslave his kind all over again... which... is honestly really fascinating, but again, without even any flavour text to work with we don't know much more than that. We can see him yelling or barking orders in his art but that doesn't really tell us all that much about his philosophical standpoint, his reasons for working with Weyland or how much he actually knows.
Beyond that I decided to track down the etymology of his name, Isaac comes from Hebrew (like many Western names, think Jonathan, Jacob, Joseph, Joshua, David, Adam, Benjamin, Daniel, Elijah, Gabriel, Micheal, Noah, Samuel and so on and so forth) and literally means "(he) will laugh" or perhaps in context "he who laughs." From the art alone this couldn't be further from the truth, but it's hard to say if this is intentional irony or if the designers just didn't know and don't care about etymology. Liberdade obviously means freedom, compare liberty, liberate, liberation or even Libertador (Mercury: Chrome Libertador) but once again, it's unclear if this is meant to have a deeper meaning or if someone just thought Liberdade sounded cool. Do all freed bioroids have the surname Liberdade, did Isaac choose his name for himself, did someone else give him this name and if so who? These are questions we may never know the answer to, but it's fun to speculate.
TLDR: One of 4 new nomadic Sysops, it has potential in glacial, advanced ICE decks but is somewhat finicky to integrate with the leading advanced ICE ID Weyland Consortium: Built to Last. Among the 4 Sysops, he's arguably on the lower end of the power spectrum, alongside Vovo and Adrian, which, is all to say that the Holo Man looks like the big brother who bullies all of his younger siblings, (seriously that card is powerful, and will probably be considered even more potent once SanSan City Grid rotates with Dawn)