Adder has mid-length, black hair, brown eyes and tan skin. She wears a sleeveless golden crop top dress, a necklace, large round earrings, two simple bangles on her wrist, and a distinctive snake armlet latched around her bicep. Around her ring finger is a ruby ring. She wears black pants/skirt with a gold belt.
Apart from the ring, all aforementioned jewelry are made of gold.
Adder is said to be extremely ruthless and vicious, being the Queen of Lykos' Criminal Underworld and the leader of a group of spies and assassins called The Order of the Black Asps.
Adder has no qualms of using others to benefit herself or her associates, brushing off Kenna's claim of her "underhanded" tactic to kill two birds with one stone as what one should expect from her. Although she is egocentric, she still respects Kenna and entitles her to support, mainly because she detests Luther Nevrakis and wants to take control of Lykos, but also because she genuinely admires the Stormholt queen for her intellect and wit.
In conversations, Adder is shown with a sharp wit, giving remarks that make her listeners uneasy. She tends to be drastic in her actions, as when she suggested to Kenna that "[the Nevrakis's] dead bodies will never be found" when the latter simply asked her to monitor them.
Adder and Raydan grew up poor in the streets of Lykos and had to resort to thievery to survive. Adder rises up the ranks and becomes a feared and respected leader of a team of assassins and thieves. She offers Kenna her poisoned dagger and helps her get into Zenobia's ball in return for a necklace. She also supports Kenna in Book 2 and Book 3, providing assassins for the final battle. At the end of Book 3 she gains control of Lykos as Kenna's vassal, although she can be persuaded to share power with Zenobia Nevrakis and/or Diavolos Nevrakis.
Her main weapons are daggers dipped in snake venom. Her use of and precision and swiftness in attacking with them are the reasons for her name. Her proficiency is such to the point where she can casually kill soldiers with a single flick of a dagger and speak of disposing three Nevrakis nobility without so much as an indication of difficulty.
Order of the Black Asps
She is the leader of a group of spies and assassins that span across kingdoms. Thus, she has access to their skills in espionage and murder, as well as wielding such skills herself, as when she disguised herself as a beggar and attempted to attack whoever gives her alms.
Raydan is Adder's brother. They are on rocky terms when they first meet in Book 2, Chapter 7 she mentions that they had a falling out in which she threatened to cut him up if she ever saw him again. Raydan regains Adder's trust and respect in Book 3, especially after he returns from spying on Empress Azura. She sends spies to help him escape the Iron Kingdom, suggests that she is willing to protect her brother and also that she understands his every move and motive. They are on good terms at the end of the book, having rekindled their brother-sister relationship.
Adder respects Kenna's intelligence, strength and determination. She acknowledges her by offering her support.
- Her real name hasn't been revealed yet.