1. Avallac'h Elven Mage
Avallac'h is a character that plays a massive role in the book series, but with the story changes made by the show, it's difficult to know how closely his role will mirror the books. His introduction in the prequel all but confirms that he will be part of the main series. It's also safe to assume that he will be a vastly different character in the main series, considering roughly 1,200 years have passed since his appearance in Blood Origin.
Avallac'h standing in a doorway holding a book in The Witcher: Blood Origin.
2. Emiel Regis Rohellec Terzieff-Godefroy Higher Vampire
Emiel Regis Rohellec Terzieff-Godefroy, better known as Regis, is one of the most intelligent and powerful characters in the entire Witcher series. The introduction of such a great character could help alleviate some of the pressure on this floundering franchise. Regis is a higher vampire, making him nearly immortal and capable of incredible feats of speed and strength. He is also over 400 years old and probably the most knowledgeable character in the series. Though he is passive by nature, Regis is a force to be reckoned with when roused.
Ciri with cuts on her face and a tattered robe, Geralt facing the camera, and Geralt with a sword on his back in The Witcher
3. Stefan Skellen Imperial Coroner
Stefan Skellen, often referred to as Tawny Owl, is a Nilfgaardian coroner and a high ranking member of the Imperial Secret Service. Skellen is one of the most nuanced villains The Witcher has to offer, making it critical for season four to include him. Indeed, it's likely he will appear in The Witcher season 4 because he is tasked with finding Ciri around this time in the book series. As fans will find out, however, Stefan Skellen has his own plans for the Child of the Elder Blood, and he may not be as trustworthy as Imperator Emhyr believes.
Nilfgaard's Army standing ready from The Witcher.
4. Vattier De Rideaux Viscount Of Eiddon
Vattier de Rideaux is the Head of Military Intelligence for Nilfgaard and one of Imperator Emhyr's most trusted advisors. Rideaux is intelligent and ruthless, and he is an integral part of Emhyr's war with the northern kingdoms. If introduced to the show, Rideaux could provide much-needed depth to the current roster of Nilfgaardian antagonists.
An image of Emhyr holding a sword in The Witcher
5. Leo Bonhart Bounty Hunter
Leo Bonhart is one of the most terrifying villains in The Witcher universe, and he is extremely likely to appear in season 4. Bonhart is an uncanny swordsman, which he proves by displaying the three witcher medallions he took from the corpses of his victims. Anyone powerful enough to overcome the mutated strength and speed of a witcher is not to be trifled with. Sword-skill aside, Bonhart is also cruel and utterly sadistic, as Ciri will soon find out.
Leo Bonhart captures Ciri
6. Zoltan Chivay Dwarven Soldier
Zoltan Chivay is a dwarf from the mountains of Mahakam, and he becomes a loyal companion to Geralt when they meet on the road by chance. Though they only travel together for a time, Zoltan and Geralt develop a strong mutual respect, which results in Zoltan gifting Geralt his sihil — an incredibly sharp and durable dwarven sword made in the forges of Mahakam. Unfortunately, Zoltan has yet to appear in The Witcher, but there is still hope that Geralt and his companions will run into him during their hunt for Ciri.
Zoltan Chivay with a hand up in The Witcher video games.
7. Esterad Thyssen King Of Kovir And Poviss
Esterad Thyssen is the King of Kovir and Poviss, and though his time on-page is limited in Sapkowski's novels, he certainly leaves his mark, both on the reader and the story. Though Kovir mostly stays out of the war with Nilfgaard, Thyssen cleverly provides financial support to the northern cause without Nilfgaard finding out. He is a uniquely likable character, worthy of an expanded role in the TV series should it opt to include him.
False Ciri and Emhyr in The Witcher season 3
8. Assire Var Anahid Nilfgaardian Mage
One of the most influential mages yet to be introduced in The Witcher is Assire var Anahid. Assire is a notably powerful sorceress, and she is a founding member of the Lodge of Sorceresses. Though she is bound to Nilfgaard and obeys Emhyr, her participation in the secretive Lodge proves that she is willing to work with her adversaries for the greater good. Assire's role in the novels is critical, though it is relatively subtle, so it would be easy for the show to replace her with a preexisting character.
Fringilla standing next to robed figures in The Witcher.
9. Isengrim Faoiltiarna Scoia'tael
Isengrim Faoiltiarna, also known as the Iron Wolf, is an influential member of the Scoia'tael and an ally of Emhyr var Emreis. Isengrim is responsible for planning the coup on Thanned, and though The Witcher did not include him in its adaptation of the coup, it's still possible Isengrim will appear in future seasons of the show. He remains a relevant character far beyond the events on Thanned, eventually rising to a position of command in the Nilfgaardian Army.
The Elves’ Scoia'tael arrive at the castle in The Witcher season 3 episode 6