Accord's power affects his behavior. Specifically it makes him hyper-aware to disorder and things that are "out of place", so much so that even minor details can drive him to homicidal rage, though he recognizes this in himself and does actively try to contain the urges his power gives where it would be inconvenient to act upon.
It is unknown how much of his original personality was subsumed by his power. Though it has left him with an appreciation of the dramatic flair. He further diverts resources to maintaining his professional mastermind image.
He believed that it was a waste of reasources to participate in Endbringer battles.
Accord is a short man. Barely standing over five feet — and tends to dress more like a CEO than like a cape. Despite this he wears an ornate wood-and-silver mask with tailored suits and walking cane.
Accord is a Thinker whose intelligence is believed to increase in relation to the size and scope of the problems presented to him; therefore the greater the problem he's given, the faster he can find a solution to it. This applies to a wide range of applications. As a test of his abilities, he devised a solution to world hunger using only a telephone and the internet in less than six and a half hours and in a further nine typed it up into a concise 150 page document outlining how to implement it. His plans are often so complicated, however, that only Taylor Hebert and Cauldron seriously considered using them.
Accord also has a minor sub-talent for creating objects with multiple interlocking parts and a sense of aesthetic harmony. He personally creates all the costumes and masks for each of the Ambassadors, even making the The Travelers costumes. His own mask is made of multiple pieces that shift in response to his facial expressions. Similarly he has created furniture that automatically adjusts itself to the user's weight and posture for maximum comfort, with apparently no electronics involved. This is not a tinker talent however as these are essentially cleverly designed pieces using mundane materials with no imput from the shard.
His plans have more direct utility. When he personally directs his ambassadors they 'always win'. Further he can accordinate plans to take out certain individuals. Being able to create elaborate physical and social traps.
Accord originally worked in Watchdog, an office handling economic oversight within the Parahuman Response Team. He took an afternoon off one day to solve world hunger and devised a plan that would solve it. He turned the sum of his work over to his employer who barely looked at it before demanding that he get back to work. He began siphoning and redistributing funds from his department but failed to account for the other Thinker that worked there. He was caught, imprisoned, and then broken out by a jailbreak specialist.
Nobody that Accord contacted took up his ideas. Government after government failed to read the documents he sent them while no one raised the subject of his work to the United Nations or any major political body.
Accord later decided that he would take the slow, steady path to victory. He amassed contacts, wealth, expanded upon his plans, and spent half an hour each morning to ensure that everything was up to date.
He had dealings with the Travelers, hiring them to attack Blasto's Lab. When Sundancer interrupted the initial meeting he claimed he would have to have the girl killed. Trickster was able to convince him otherwise by offering up the 'true' person responsible for the interruption.
Before they moved to Brockton Bay Accord outfitted the Travelers with their matching red and black costumes.
In order to push out the newly arrived mebers of Fenrir's Chosen, Accord called a truce with Blasto so that he could construct a powerful creature that would send the neo-nazi's out of town. Accord's Ambassadors were attacked in the building they were stationed in, hampering the plan to turn on the Plant-tinker once he had completed his project, as the tinker was kidnapped by Bonesaw for her own ends. As a consequence of the Slaughterhouse Nine coming to Boston Accord lost all but two of his current Ambassadors.
Accord was killed by Cody a former member of the Travelers who had been sold to the Yangban by Accord. Cody was the reason Accord's meeting with the Travelers had been interrupted when they visited Boston prior to the Travelers moving to Brockton Bay.
During the New Delhi attack, Cody rebelled against the Yangban, killing Accord and wounding Chevalier and Tattletale.
↑ 2.02.1Accord has resources, a long reach, and on the smaller scale, he's a trapmaster. He's much like Coil in some ways, but surrounds himself with capable, ambitious parahumans instead of mercenaries, and plays up the 'trip hidden switch, open pitfall trap' angle.
When he makes it one of his ongoing plans to remove you from the picture, things get really, really bad for you. He's perfectly willing to pull out all the stops to clean up a mess, to kill without any hesitation, and because it's so integral to his reputation that he conveys this image, he is very committed to seeing it through. -
Wildbow on Reddit
↑"You would have me risk good help on fruitless fights against immortal killing machines," Accord said. - Interlude 20
↑Accord – A thinker of short (five foot) stature, with an ornate metal mask. Hails from Boston. Gets smarter as scenarios get more complicated. Likes order. - Cast (spoiler free)
↑Accord wasn’t the most influential figure in Boston. That was why Trickster had approached him. He didn’t even look like a supervillain. He looked like a CEO. Only an ornate mask with curling, overlapping bands of dark metal trimmed in silver marked him as anything more. His hair was oiled and neatly parted, and his white suit had been brushed clean with immaculate care. Trickster doubted there was even a fingerprint or a glimmer of tarnish on Accord’s silver tie pin. For all his presence, Accord was barely over five feet in height. - Excerpt from Migration 17.8
↑Accord was a thinker, and the running theory on his power was that he got naturally smarter as the problems he was addressing got more complex. It gave him an intuitive understanding of groupthink, politics, and convoluted designs. - Excerpt from Migration 17.8
↑Accord – A thinker who is suspected to have intelligence that scales proportionately with the size and complexity of a problem, is a masterful counterattaker fond of elaborate traps, a skilled designer and a cunning policitican. Driven to find order by the rigors of his power, he is ruthless and unyielding when confronting any rulebreakers or anyone who might cause chaos and disorder. A onetime associate of Coil. Accord is short in stature – barely over five feet in height, and wears a neat white suit and a complicated mask of overlapping threads of metal that mimics his facial expressions. - Cast (in depth)
↑ 8.08.18.28.3It was only one imbalance, one irregularity, but it had been an important one. It had nagged at him, demanded resolution. He had to prove it was possible.
So he’d siphoned the very funds that his department was managing. It hadn’t been hard to redistribute some of the wealth that the villains and rogues were trying to manipulate. One ambiguous evil for the sake of an undeniable good. He covered his tracks flawlessly.
In the process, he failed to account for the full breadth of his newest coworker’s talents. Thinker powers interfered with one another, and despite his ability to work with that particular drawback, even help them to work in concert, the clairvoyant had found him out. He’d been caught, jailed, and subsequently freed by the jailbreak specialist he’d contacted well in advance. - Excerpt from Interlude 20
It varies from tinker to tinker. In the tinker's handbook, I break tinkers down into types. Every approach changes in little ways. By and large, however, it's a case where you get inspiration like any creative or engineer might, and as you decide to put it into action, the ideas fall into place in your head.
Some tinkers might tune out at some point in the process, they might get into the zone, black out, or lose track of time. Other stay lucid but might only do certain things at different points in the project because they 'feel right' or because of ideas in their heads about wanting things to stay balanced or to maintain a seemingly logical flow of A to B to C, conveniently skipping why it was seemingly logical in the first place - if pressed they would have a hard time explaining.
It seems incomplete because it is an incomplete process. In the background, the shards themselves are taking a hand in things, supplying an extradimensional limb to hold something in place that the tinker isn't wholly aware of, or a power-driven equivalent to a screwdriver in another reality that connects the aforementioned A to B. This is why tinkers have such a terrible time trying to teach others how to build their tech, and why another person can't just sit down at a table and copy everything the tinker does.
The shards are helping to put ideas in the tinker's head or round out ideas as the tinker has them, supplying blueprints or outlines, or giving them a 'feel' as to how easy it will be to put something together. When the tinker pulls out a tricorder-like device and scans a power signature, the shard helps supply the language and interpretation for the tinker. During the build process, the shard itself supplies a helping hand, or outright takes over at a given period of time, during which time the tinker isn't wholly there (blacked out, in the zone, lost in their work) and the shard is doing the work. Sometimes this is pronounced to the point that the tinker isn't wholly sure what they'll end up with.
- Wildbow on Reddit
↑It is definitely possible to avoid the hit. That's not really the problem.
The problem is that he's thorough and he acoordinated four or five independent hits against you, while pulling in favors with people who you'd normally turn to for help or sanctuary.
↑The Watchdog group is the group Accord belonged to. Parahuman thinkers and investigative bodies keeping an eye on economy, politics and other possible shenanigans behind the scenes. -  from a comment by Wildbow on Reddit
↑In Accord’s defense, he was planning on framing Blasto, and not letting the tinker get to the point where he really finished a dangerous project; let him start working, get caught up in things, and then disappear, leaving a message for the heroes so they can stumble on the guy with piles of classified material and a possible Endbringer-in progress (note how the place is nice, but it’s not Accord’s real headquarters, as they were described in the last chapter of Migration).
I was going to have something like that in there, but couldn’t find a place for it at the end that wouldn’t kill the tempo. - comment by Wildbow on Interlude 19.x