The same story also reveals the Darkling has a half-sister named Ulla, mothered by Baghra.
Alina and The Darkling are Connected Even When It Is Severed
With the unnatural tether gone, he still believes they are connected through their abilities. He has always wanted her light to balance his shadow. Their connection persists because of what The Darkling believes Alina to be.
While searching for the last amplifier, Mal and Alina find out the truth about Mal's heritage. He is descended from Baghra's sister, making him a great-nephew of the Darkling. It also makes him an amplifier. He accepts this fate, understanding and willing to die for Alina.
Many centuries ago, known then as the Black Heretic, the Darkling returned home to his partner Luda, who was also a Grisha Healer.
During the second season, we find out Baghra herself is the daughter of Ilya Morozova, making the Darkling his grandson.
In When Water Sang Fire, there is a scholar around whom "the shadows seemed to shift as he passed, pulled along by him like a tide." This is the Darkling. The same story also reveals the Darkling has a half-sister named Ulla, mothered by Baghra.
It turns out Mal is descended from Baghra's sister, making him a great-nephew of the Darkling. Upon this discovery, Mal makes Alina promise she will kill him for his power if she needs it.
Zoya was initially infatuated with the Darkling.
The Shadow Fold was created roughly 400 years prior to the events of the series and the Darkling was already an adult by then. An estimate would put him at 500 years of age, if not a bit older.
Nikolai asks Alina to return with him to Ravka and help him to defeat the Darkling. He also proposes marriage to her, suggesting that such an alliance would make both of them stronger and allow them to unite the First and Second Armies against the Darkling.
Neshyenyer being from Shu Han adds another layer to the Mal connection: Both Mal and Alina are part Shu, and they've experienced racism all their lives because of it. (Shadow and Bone's handling of race has garnered compelling criticism.)
Let's talk about Mal for a second. Mal was oblivious to Alina's love from before book one even began. He slept with Zoya and countless others before he realised who was waiting by his back door.
Zoya destroys the remains of The Darkling when she realizes what is happening, but The Darkling's spirit goes into the body of a man named Yuri Vendenen. So, while The Darkling does return in some form, he does not return in the one that people recognize him as.
Alina is automatically powerful just by being the Sun Summor. She destroyed the Fold, which was with the help of three amplifiers. Because of those amplifiers, she is in third place. Coming in at number two, we have the Darkling.
Basically, Kirigan is very lonely as an immortal being, so he's very invested in the idea that he and Alina belong together. She's been in love with her best friend, Malyen “Mal” Oretsev (Archie Renaux), since they were kids together in the orphanage of a small village called Keramzin.
General Kirigan / The Darkling
The villain of Shadow and Bone seasons one and two is the Darkling, the former commander of the Second Army. He is a Shadow Summoner, and the creator of the Shadow Fold. He was born centuries ago and his mom is Baghra (see below).
Ulla is a half-sildroher songcaster and the half-sister of The Darkling via their late mother, Baghra. She is also known as Sankta Ursula of the Waves.
The Darkling felt a lot more like a manipulative groomer taking advantage of a young girl than a villain who looked like every other YA love interest.
In Shadow and Bone, age is often heavily tied to the amount of magical power a person has, making the Grisha able to live the longest.
Rather than raping or assaulting women, the Darkling tricks Alina into falling in love with him, his goal being to take Alina's power for himself and effectively enslave her.
In the book, we are led to believe that she hates Alina because she is The Darkling's favorite and that she is jealous of her. In the show, Zoya is still envious of Alina, but it goes a step further. Alina is part Shu and Zoya makes sure to point it out and intimidate Alina because of it.
Siege and Storm
Alina urges Genya to come with them but Genya cannot and is left behind. Towards the end of the book when the Darkling finds Alina, we find out that the Darkling unleashed nichevo'ya on Genya because she spared Alina. Her skin is scarred all over and she only has one eye left.
In this adaptation, Mal is Inej´s brother. Inej doesn't have a brother in the book series. Why make that change unless it is a big deal? Seems unlikely, Inej's brother grew up with her and their family, while Mal grew up with Alina in the orphanage.
This was later found out to be false as Morozova's daughter, and by extension, Mal, was the third amplifier, by virtue of her resurrection. The firebird's path of flight was said to be Ravka's original borders and that the firebird's feather was what protected the first Lantsov King in battle.
In the Netflix show, Alina Starkov's mother was Shu, and her father was Ravkan.