Why Magnus Carlson
The presumably greatest chess player of all time (if not, definitely at least #2 behind Kasparov).
Magnus’s strengths are mostly his Intuition and Positional awareness.
In chess, there are mainly two types of players: intuition-based and calculation-based.
What gives Magnus the edge over others is his ability to feel positions better than everybody else. Whether it's innate or comes from hundreds of thousands of games of analysis (most likely both), he can feel out moves at an almost superhuman level.
While every strong grandmaster has the intuitive touch (sixth sense) for the right moves, Magnus can find these moves with more precision, less time, and greater feel of the momentum.
Intuition
In multiple interviews, it is obvious that many of the moves he plays or ideas he comes up with aren’t based on calculation (at least initially). He often just feels things like attacking on a certain side of the board, knowing which squares will lead to blunders, knowing when the opponent is trying to trick Magnus, and knowing when to play fast/slow down.
In Kingdom, the types of generals in the series are very similar to the types of chess players: instinctual general vs. strategic general.
"Since instinctual types follow their intuition more than a strategy by the book like a strategist, they often tend to charge into the battle firstly, then secondly adapting to the battlefield and have a keen eye for even the slightest changes as the battle proceeds to adapt in the best possible way to hold their advantage." - Kingdom Wiki
Although Magnus doesn’t really follow the “charge into battle” side of the instinctual generals, much of their way of attacking is similar to how he approaches chess. Magnus is very much like General Ouki. Although they both have superb intuition, they are able to calculate/strategize at a very high level as well. Although intuition and calculation may seem inversely different, intuition allows you to know when you should calculate.
Cause of his Intuition
It is easy to say his intuition is just a God-given talent, but it is much more than that. Yes, his ability to remember thousands of games is most likely a genetic gift, but his mentality and lifestyle facilitate that much more than his genetics.
His life revolves around chess.
He has mentioned many times that he is constantly thinking about chess positions. And when someone is constantly enveloped and consumed by something, their mind starts to think and understand it at a deeper level.
He has analyzed millions of games.
Whether he has played in them or not, he has broken down and understood millions of chess positions in his life. This has created a gigantic web of patterns for him, which he is able to retrieve through pattern recognition.
Winner’s Mentality
Magnus understands that to be the best, you have to have absolute belief that you are the best first. Although many label him the arrogant title, many of his interviews convey the idea that he is not trying to be braggadocious, but rather, he is sincerely expressing what he believes.
It is easy to tell this from his mannerisms when the topic of being the best comes up. He never wants to brag about his best title, but he simply states the objective reality to convey his answer to a question.
Objectivity
“I’m not really the person to have idols. I admire what people can do, not necessarily the people themselves.” - Magnus (FIDE World Championship 2018).
It is apparent through this quote and other interviews that he mainly judges decisions/moves/positions rather than the people themselves (to be fair, he definitely has judged people in the past, but most of the time, when he is questioned, he mainly talks objectively).
For a while, I didn't completely understand what he meant by this and why he held this principle. But over time, I've started to see that people are nowhere close to perfect. We are quick to idolize or demonize people when we really have no idea what's going on in their head or behind closed doors.
It is in focusing more on the individual and independent ideas and actions from people that we can prioritize taking in what could be helpful to us rather than spending time judging someone for whom we really have no proper context for.