Orikan the Diviner
>
"In regione caecorum rex est luscus (In the Land of the Blind, the one-eyed man is king.)"
- – Desiderius Erasmus, Adagia
Orikan the Diviner is one of the most powerful Crypteks in the entire Necron Empire. In particular, he is an astromancer, specializing in reading the future from the patterns and motions of the stars.
Lore
He is acknowledged as the very best in his field. Apparently, he was able to predict the Fall of the Eldar, the Horus Heresy, the Great Rift and the coming of the Tyranids sixty million years in advance, which gives him a massive ego. He was a member of the Silent King's court and the only one among the nobility who knew the C'tan's offer of robotizing the Necrons would have a steep cost (If he rejected the offer, then why is he a Necron, you ask? The other Necron lords dragged him to the biotransference IN CHAINS). But Szarekh spurned his warning, resulting in Orikan refusing to serve any master but himself.
He has no respect for the nobles who hire him, but his reputation renders him effectively immune from punishment, because any Overlord who wishes to harm him is paralyzed by the thought that Orikan must have foreseen that sequence of events and taken steps to prevent it or take pre-emptive vengeance.
In reality, Orikan is not quite as good a forecaster as the Necron nobles think he is. He can predict events in more detail than any other astromancer, but even he makes mistakes. He makes up for this with his mastery of time travel -- if his prediction is erroneous, he either goes back in time and manipulates events to conform to the prediction (in spite of the unforseen events that this can bring about later) or tells his past self what will happen (as of 9th edition lore). However, this can risk causing a HUGE temporal paradox, and the universe is messed up enough as it is. Plus Chaos can mess with Orikan's predictions, and the entities of the Warp can perceive time in a non-linear fashion so he fears they'd come after him if he uses time travel against them too much.
It is clear that despite his arrogance he is aware that even someone like him is powerless and weak in the Universe, having fear of both the C'tan and the Chaos Gods (Slaanesh's awakening mentally scarred him so much he had to isolate and meditate for a hundred years, and he only felt a small portion of what the Eldar can feel from the massive Warp disturbance)
He and Trazyn have something of a history, even before Bio-Transference. The pair have spent several millennia dicking each other over; dragging each other into frivolous court cases, staging proxy wars for shits and giggles, and both being manipulated into almost releasing several shards of the Deceiver. Whilst they still very much hate each other, both admit that they are as close to peers as they are likely to find.
Tabletop
Orikan's big plan is to somehow harness the power of the alignment of the stars in the indeterminate future. Instead of reversing biotransference and reverting to a fleshy body like everyone else wants to, Orikan intends to transcend necrodermis and become a being of pure energy, blazing the trail for a new kind of Necron. He has a chance of doing this in miniature during games of Warhammer 40,000 with a special rule called "The Stars Are Right" (feel free to make Cthulhu jokes as desired). He gains a hefty stat boost if you roll equal to or under the current turn number (and he no longer reverts if this roll succeeds again). For maximum nostalgia, go full Mumm-Ra and "invoke the ancient spirits of evil" whenever you roll that die (the original rule actually included evil laughter: "Bwahahaha!").
There is a bit of evidence to suggest Orikan is a C'tan who managed to avoid the Poké Ball prison. His complete disregard for the necron nobility, the fact he's actively avoiding close scrutiny, and the small tidbit about his empowered stats being identical to that of a C'tan Shard. His equipment helps align him even further, giving him their trademark 4++ and AP2. This could mean that he's one of the weaker C'tan, being only as powerful as a small piece of one of his brethren, but could also imply that he's only managed to collect a small portion of his true strength for the time being. Maybe he is a freed shard or something, but minor shards only have intellect on par with simple animals, and masquerading as a brilliant scientist is way above their capabilities. Or maybe Orikan Empowered is just the Necron equivalent of Daemon Princedom. Or maybe he's really Dio. But probably not, he’s likely just a dick as seen in the Infinite and the Divine. But a powerful one. As a nod to the statline, at the climax of the book he achieves maximum power and temporarily becomes something very similar to a C’tan, appetite and godlike contempt for all life included.