Phineas is kind of a genius and it takes the form of him being incredibly good with technology. Like, ridiculously good. For all that he had less than 10 minutes of screentime, he was able to make a lot of advanced tech; while Phineas does not have access to 99% of these things in-game, of course, he is fully capable of making these and similar things again if he has access to the proper materials.

While he's much more limited in this sense than Chameleon or Quentin Beck, Phineas has gone out in the field before for their jobs and is far from incapable of putting on a decent act. He has canonically pretended to be a hostage at a bank robbery and a crewman for the mayor's yacht. I'm pretty sure he was also bluffing like hell himself when he called Spider-Man's bluff in "Shear Strength," and that he put on a good "totally innocent legal property owner" act for the police when they came to the prop house to arrest Quentin Beck('s android) in "Blueprints." And he's pretty personable, which leads to...

Now, admittedly, this is a lot more useful in his canon universe. Phineas Mason has worked with Chameleon, Mysterio, Doctor Octopus, Vulture, Electro, Kraven, Sandman, and Rhino, and he's also made things for Tombstone, Shocker, Ricochet, and Ox besides. In AUs and crossovers he may or may not have any of those connections, of course. But this is also to show that he's pretty good at finding contract work and forming professional connections. His inventions are worth every penny and he's good at convincing people of that! He also seems to be on at least reasonably good terms with everyone he's ever worked with or for as well as them always being satisfied with his work.

After Chameleon's attempt at impersonating Dr. Curt Connors to steal "the alien life form" for an unnamed military general fails, Phineas Mason is there playing cards with Quentin Beck when they get news that they aren't going to get paid for this one. Chameleon's gotten the idea to impersonate Spider-Man, however, framing him as a criminal and reaping the benefits, and enlists "all [Phineas's] mechanical ability."

The next day, Phineas is there alongside Beck being "held hostage" as Chameleon robs a bank disguised as Spider-Man. Phineas surreptitiously slips on a pair of high-tech goggles over his glasses that allow him to take pictures of the robbery and anonymously email them to J. Jonah Jameson at the Daily Bugle.

Later that evening, the mayor is throwing a fancy re-election party on her yacht to solicit support for the upcoming election. Phineas and Beck sneak on board as a crewman and a waiter respectively, while Chameleon first gets on board by pretending to be Norman Osborn, then sneaks away to change into the Spider-Man disguise instead. Phineas waits outside, and when things go south and Chameleon and Beck run out with the loot, uses his watch to remote-control a waiting speedboat over to them. When Spider-Man shows up, he throws a frisbee-like drone, of sorts, that homes in on Spider-Man and starts firing a laser weapon, though Spider-Man quickly destroys it.

Black Cat grabs Phineas and Beck before they can jump into the getaway boat; Beck drops a smoke-bomb to attempt escape, but she promptly knocks them both out. All three are arrested and put in the back of a police van, but Chameleon escapes disguised as one of the cops before the van can even leave the harbor, to Phineas's apparent satisfaction.

After all of Mysterio's crimes, after Beck's seemingly arrested and the police have left, Phineas assures the real Beck that they're gone and reveals that they'd arrested an android instead. Phineas chews Beck out a little for "[making] your android look just like you!" and is exasperated at Beck's dramatic reasoning that no one else should be allowed to take credit for the role of Mysterio. He then contacts the Master Planner to let them know that the police had come and gone without finding any of the technology that Mysterio had stolen, and that it's all still in their possession.

Tinkerer is keeping an eye on the cameras outside the Big Sky Billiard Room when Spider-Man finally gets a little info out of Patch and finds out that Mysterio's employer is called the Master Planner. He immediately alerts Master Planner that "Spider-Man's closing in," and is told to proceed in breaking Vulture, Sandman, and Rhino out of Ryker's, breaking Doctor Octopus and Electro out of Ravencroft, and contacting Mysterio and Kraven.

Tinkerer proceeds to somehow get a hologram of Adrian Toomes into the cell that Vulture and Mysterio share, as well as loosening the head from the Beck android so that it falls off when the guard touches it! And actually break the three out of Ryker's, though it's not shown how. He tells Kraven to go and liberate Doctor Octopus and Electro, though Doctor Octopus has seemingly regressed back to the meek and terrified Otto Octavius and refuses to go with them.

He leads Kraven and Electro into the main room of the Master Planner's secret lair, where everyone else is already gathered, and does the introductions just to make things official, even though he knows most of them know one another already. He then kinda low-key-dramatically introduces them to their "host and benefactor," the Master Planner, who shows up only as a dark silhouette on the large computer screen at the front of the room. The Master Planner expresses regret that Doctor Octopus refused to join them, since they now cannot be the Sinister Seven; when Rhino asks if Tinkerer doesn't make seven, Mysterio assures that he's "strictly tech support" and "useless in a fight." They proceed to make a plan, or rather listen to the Master Planner's plan, on how to take out Spider-Man.

When the plan fails, Tinkerer extracts all of the Sinister Six from where they're restrained, as well as sending Doctor Octopus's metal arms to Ravencroft to "forcibly retrieve" Otto Octavius.

Tinkerer is there with Vulture and Electro when the Master Planner arrives and is revealed to be Doctor Octopus, and has obviously been in on it for a while now! Ock explains why the subterfuge, then asks if they're ready to begin; Tinkerer affirms with some real Mad Scientist Mischief energy that all they have left to do are "calibrations and testing."

Tinkerer keeps an eye on the wireless server while Doctor Octopus mentally hacks into a remote detonation system in order to try to bring down a building on Norman Osborn. He's dissatisfied with fluctuations that he noticed and asks Electro for more power in reserve, and Ock soothes him; it's revealed that Ock's brain is now wirelessly connected to every computer in New York City, and that Tinkerer and Vulture put together the system from the technology that Mysterio stole.

Ock can't hack into the isolated system that holds the global portal codes at Homeland Security, though, and sends Electro and Vulture out to kidnap Gwen Stacy, giving the Master Planner leverage against her father, Captain George Stacy. Tinkerer is sent out with them as the getaway driver.

While the kidnapping itself goes off without a hitch, the getaway unfortunately goes very wrong. As soon as Ock alerts them that they're being followed by Spider-Man, Electro starts blasting at him out the window, making it impossible to ditch him as Tinkerer had been planning. Electro loses track of him after some explosions obscure visibility, and Spider-Man promptly kicks his way in through the windshield, giving Tinkerer pretty visibly bad whiplash and causing the entire van to skid out, do a nearly complete roll, and crash into a building.

Electro escapes; unfortunately, Tinkerer does not. Spider-Man yanks him up to the roof of the building and proceeds to threaten him into telling him where Gwen is being taken. When that doesn't initially work, Tinkerer calling his bluff that he'd "do anything rash," Spider-Man throws him off the building and lets him fall a pretty long way before catching him by one leg, smacking his head into the side of the building. Tinkerer says he "knew [he] wouldn't really let [him] fall," and Spider-Man drops him again, catching him by both legs that time and all but saying that if he gets a third strike he's dead. Tinkerer, who's lost his glasses to the street below by that point, is terrified enough that he tells Spider-Man where the base is and exactly how to get inside.

Tinkerer is revealed to have made skill enhancement suits for Fancy Dan and Ox, the two Enforcers who didn't have supervillain costumes and powers already. Fancy Dan, as Ricochet, now has a suit that lets him use kinetic energy to absolutely pinball around, complimenting his already acrobatic and martial arts heavy fighting style; Ox, who is uninterested in using any other name when Tinkerer asks, has a suit that boosts his already immense strength and ability to take hits (as well as possibly upping his speed a bit!). It turns out that this project was a commission from the Big Man of New York City, Tombstone, who fully approves of the upgrades.

Before canon, Phineas Mason had been working with Chameleon and Quentin Beck for a few years. At first, Chameleon had worked with them both separately, but when a job required both of them at once they discovered they all work well together. They aren't exactly a unit, because they all go and do their own things, but none of them have ever once declined the opportunity to work together or lend each other a hand, either.

That game where Phineas and Beck try to flick cards through the air into a hat is half a game and half a way of testing out new tricks of the trade. The only two rules are that they both must remain seated the entire game and that as long as a card ends up in the hat, no matter how it gets there, it counts.

The Symbiote job isn't the only time Black Cat's competed with this particular team; it's happened a handful of times before. She wins some, she loses some. She and they both have to do prep and look into things, but because Black Cat is so hands-on and doesn't always have to make new disguises and inventions to do a job, she sometimes beats them to a target. This is kinda especially frustrating for Phineas, in a [FLINGS HANDS INTO AIR] way, since she can often physically slip past security systems he has to take a just little longer to actually disable. Whenever they do happen to go after the same targets, whoever gets there first nearly always does so "by mere minutes."

Beck and Phineas worked together to make the Spider-Man suit for Chameleon, strictly speaking, but Phineas was responsible for the springs in the feet, the suction cups on hands and feet, the subtly integrated communications, and the rope/"web" shooters. Chameleon wanted to get started immediately, so Phineas had less than twelve hours to put that stuff together, and he never really had an opportunity to try to make it any better later. He's actually pretty embarrassed by the quality of it!

Nobody made their escape into the speedboat while Spider-Man was busy with the laser-drone because there had been no way to assign it to a particular target. It was literally going after the closest heat signature that was moving, so the three of them had to stay pretty still until Spider-Man smashed it.

Phineas is indeed useless in a fight and every time he goes out in the field, even as a very minor participant or getaway driver, he's even more convinced that he really wants to stick to inventing things and watching people use his inventions from afar, and helping from home base. At this point not many people can get him to actually be on or near the scene of the crime when shit goes down.

Despite Beck saying "you put me away" to Spider-Man, that was overly dramatic. In the first episode, Officer DeWolff argues to her partner that almost all of the perps Spider-Man catches end up walking, and with Chameleon gone, a bunch of confused witnesses, and Spider-Man not exactly able to take the stand himself, neither Phineas nor Beck served any time and Phineas doesn't even have a criminal record. Yet.

The Master Planner reached out to Phineas and Beck shortly after the events of "Persona," commissioning a supervillain and the theft of a lot of very specific tech. Tinkerer was in fact so key to the Master Planner's... master plan... that he got let in on the true identity of Doctor Octopus almost immediately—he was the first of any of them to find out, in fact, if only because Vulture and Electro were still in Ryker's/Ravencroft until the day before Christmas Eve—and very swiftly became a part of Ock's most trusted inner circle. The only people in this inner circle, and the only people who ever found out that Doctor Octopus was the Master Planner, are Tinkerer himself, Vulture, Electro, and (though we don't get any proof of this in-series) Mysterio. (Well, Spider-Man ended up finding out too. Because Spider-Man.)

While Beck provided the specifics for the Mysterio costume, as well as things like the invisible odorless dazing gas, Phineas was the one that made the costume itself as well as all of the advanced tech that Beck used (and uses) as Mysterio. More than that, he was actually in the building during the Spider-Man fight and was the one controlling some of the stuff that was attacking the superhero, like the swinging ax, the giant killer teddy bear, and the multitude of dart shooters. That was also not a fake Beck that Spider-Man captured. (The real Beck was missing the glove that Spider-Man destroyed!) Sometime between Spider-Man swinging away and the police arriving, Phineas helped get Beck free and hidden and put the android in the webbing instead.

Phineas legally owns property all over New York City. It's all abandoned places that aren't in use, perfect for secret hideouts and criminal activity. The boarded-up hair salon and the prop house were both actually his property.

Phineas Mason only very recently started going by the name of the Tinkerer, sometime between mid-November ("Persona") and early December ("Blueprints"). It was a recent decision to start advertising his black-market services—specifically commissions for more extreme tech and "superpowered" suits—more widely to NYC's criminal element. Since this is the time of the supervillain, Doctor Octopus did nothing but encourage him. Officially, Phineas chose "the Tinkerer" because he doesn't want people who hear his name to know how good he is unless they fully know his reputation, but he also likes the way the word sounds and has pleasant associations with it; both Chameleon and Beck have poked fun at him for "tinkering" with and making all kinds of perfectionistic changes and upgrades to inventions he'd already officially finished.

When Tinkerer broke everyone out of Ryker's, he was making extensive use of drones that had been inside the Beck android. That's actually the primary reason why its head was unscrewed! One attached itself to the wall beside Vulture's cot and projected a hologram; others attached themselves to the walls to project undisturbed walls where lasers had actually cut holes through, and others, well, cut holes with lasers. He also once again remote-controlled a speedboat up to the island (with Vulture's costume on it) so that the three of them could get back to the mainland.

By the time "Reinforcement" rolls around, Tinkerer and Mysterio have things set up so that Mysterio never even gets restrained by Spider-Man in the first place, much less arrested. From now on it will always be a Mysteriobot, or rather, an android that looks like Beck underneath the Mysterio costume. And one that can pass for human even for 2+ months at a time in a prison environment.

Despite rolling his eyes at Mysterio's theatrical bent and occasionally vaguely despairing about "actors" re: Mysterio and Chameleon both, Tinkerer absolutely has a dramatic streak himself and has a blast leaning into the "evil scientist supervillain" persona, at least in a mild way. "Allow me to introduce our host and benefactor, the Master Planner"; "Welcome to your lair, Master Planner"; and "All that remains is calibration... and testing" were all him hamming it up and he absolutely enjoyed it.

Tinkerer didn't actually install any of the cameras being used to spy on the city, he's just hacking into all of the cameras that were already there. He and Doctor Octopus agree that it's absolutely creepy that there are cameras everywhere and also agree that they are absolutely going to take advantage of it.

Tinkerer only even gets sent out as the getaway driver because Doctor Octopus only let the smallest handful of trusted associates in on this particular plan. Vulture needed to take to the air and Electro needed to knock Gwen unconscious, so if anyone was going to be waiting in the van at all it needed to be Tinkerer. If Mysterio is in the inner circle, Beck can't exactly go out in public while that android's doing time.

Electro only gets away and leaves Tinkerer because Tinkerer was temporarily unconscious and pretty much impossible to get to and grab. He was strapped in, he was on the driver's side, the van was on its side with the driver's side door trapped against the ground, and when panicking Electro can't control the electricity so well.

Tinkerer did make it out with thankfully minimal injuries, though. Whiplash, a knot on the back of his head, a bruise on his forehead, a pulled muscle in his leg due to Spider-Man catching him by only the one that first time, with nothing broken and no concussions. Even the crash itself already had him pretty freaked out, though, much less Spider-Man dragging him up to the roof (and almost certainly via web and not stairs); when Tinkerer "called [Spider-Man's] bluff" he was actually kind of bluffing himself and was never completely convinced that Spider-Man might not just drop him. This has not made him more eager to get back out in the field rather than just making shit in his workshops from now on. Also, due to misunderstandings about the Symbiote while it had Peter as its host, Doctor Octopus is under the impression that Spider-Man was about to kill them, so at this point Tinkerer isn't sure that Spider-Man is actually 100% against killing his enemies. Misunderstandings and escalations that may well lead to big trouble.

Personally, I do think that Quentin Beck is in Doctor Octopus's inner circle; Mysterio was the one to steal all of the components necessary to for Tinkerer and Vulture to build the machines, and it would make sense if Mysterio was the one to retrieve Tinkerer before the cops arrived to arrest him, given that he was probably left hanging halfway up the building, Electro was in custody, Doctor Octopus was sent into a retreat, and Vulture had been attacking Homeland Security's New York HQ as a distraction. Mysterio does at least have lightning platforms and a flying dragon robot. This one's kinda more about Mysterio than Tinkerer but I think it's pertinent since it explains how Tinkerer even escaped.

When making Ricochet and Ox's skill enhancement suits, Tinkerer secretly installed failsafes in them, and can now completely shut down their suits remotely at any time he likes, making them appear to short out and lock up completely, rendering at least those two of the three Enforcers a non-threat. (He offered to upgrade Shocker's suit, too, but Shocker himself declined, more's the pity.) He's also given Beck the ability to do the remote shut-down as well, worked into the Mysterio costume so that it can be done in standard Mysterio "casting a spell" style. It's better to be prepared just in case one of the most powerful crime lords in New York does decide to send hitmen after you and/or yours. Tombstone would not be surprised to find this out; Tinkerer will keep working with him anyway. Nothing personal, just business.

Neither Phineas nor Beck were working with Chameleon while the latter was pretending to be Norman Osborn; Chameleon was actually using the Osborn mask Beck had already made way back in "Persona" for the yacht party robbery!