|“||I know I'm not supposed to tell you this...but I love you||”|
—Adrian tells Sydney, in The Indigo Spell
Sydney Sage and Adrian Ivashkov's love affair is complicated and one of the central focuses of the spin-off series Bloodlines. The main factors complicating their love include their race difference, beliefs, etc.
Sydney Sage saw Adrian Ivashkov in the video footage at Las Vegas when Rose Hathaway was there to turn Dimitri Belikov back into a Dhampir. When Sydney saw Adrian, she commented that he was cute for a vampire. Despite not having met, Adrian seemed to remember her name. She mentions that he is hot for an evil creature of the night.
Sydney was at Court when she was captured along with Sonya at the Mastrano's home. Adrian mentions her as one of the "victims" of Rose's happy ending.
When she is sent to Palm Springs to protect Jillian Mastrano Dragomir, Sydney Sage once again sees Adrian Ivashkov as she comes with them to bring Jill to Palm Springs. At the beginning Sydney dislikes Adrian because he is a Moroi, but later on they become friends when she finds him smoking outside of Clarence's house. They begin talking; when Sydney calls him brilliant, Adrian begins to tease her and screams out that Sydney thinks he is brilliant.
One night, Sydeny is wakened by Jill telling her to go get Adrian, who is stuck at Long Beach after a night of partying. Sydney goes to pick up him up and comforts him, but tells him that drinking doesn't take away anything. It is during this time that she also finds out Adrian brought Jill back from the dead, making her Shadow-Kissed, which she finds brave and selfless of Adrian.
They quickly become friends as Sydney spends large amounts of time at Clarence's House; she notes that she likes spending time with Adrian. Together they help each other find out the reason for the tattoos at Nevermore, when Adrian distracts the tattoist for Sydney while she investigates. Sydney offers to help Adrian get out of Clarence's home and into his own place, and also helps him enroll in college for art. Together, they find out that Keith has been the one giving vampire blood to Nevermore for the tattoos.
At Jill's fashion show, Sydney and Adrian bicker with each other. In the end, they have become close friends.
Sydney and Adrian seem to have grown closer, shown by him sending her a text that makes her laugh, which is said to be a rare thing. When Sydney comes to Clarence's house, Adrian is overjoyed to see her and even gives her a diet coke that he promised to give her. While back at Amberwood, Trey Juarez sets Sydney up with his friend Brayden Cartwright, who is said to be her intellectual match. When Sonya asks Sydney to give up her blood to be tested on, Adrian becomes highly protective of her and tells them that they cannot as she doesn't want to, which Sydney feels grateful towards him for.
Adrian askes her to drive him to San Diego to meet his father so that he can get into contact with his inprisoned mother. Sydney agrees to drive him and accompanies him to see his father, where she witnesses Nathan Ivashkov rip up everything Adrian has ever done or tried to do. At this point, Sydney defends Adrian by telling Nathan that his son is a special person. To cheer him up, she buys him a slushy, but also buys herself one to please him, despite her not eating anything with sugar in it.
When back in Palm Springs, Sydney asks Sonya and Dimitri to talk to Lissa about convincing Nathan that Adrian is trying to improve; due to this Nathan gives his son money and a car. At the Halloween Dance, Adrian calls Sydney and askes her to drive him back to his apartment because he was drunk. She leaves her date with Brayden to take Adrian home, where the power is out. He tells her that he drinks to keep the Spirit at bay or else he will go insane, but Sydney tells him he is not going to go that way. Adrian asks her why she asked Sonya and Dimitri to help him, and she tells him that she wanted to help him because she felt helping him was a good thing. They nearly share a kiss, but the power returns.
They both sign up for a self-defence class, but Adrian is relucant to touch Sydney and eventually quits. Adrian's car is a manual, but he pretends he doesn't know how to drive a manual in order to spend time with Sydney, as he has fallen deeply in love with her.
After Brayden breaks up with Sydney, she instantly goes over to Adrian's, where he confronts her about her eating habits, but she corners him about his lying regarding manual driving. To this, Adrian tells her that he made up things just so that he could spend time with her. Afterwards, Adrian kisses Sydney and she kisses him back, thinking that when she kisses Adrian all thoughts of logic and reason leave her mind. However, she breaks off the kiss and tells him that they can't be together because she is human and he is a vampire, alongside her beliefs in the system of the Alchemist. Adrian tells her that he is the only one that truly and perfectly understands her, but despite this Sydney walks away, looking back at Adrian as her heart breaks.
Sydney continues to avoid Adrian, and he is moody around her because of her rejection. When catching a plane to Philadelphia, Sydney is seated next to Adrian when the flying company changed her flight. Adrian tells her that he will contiune to love her from afar, despite her not loving him. Sydney argues with him on that, to which he tells her that she is already half-way in love with him.
At the wedding, Sydney comments that Adrian looks extremely attractive in his formal outfit; when he sees her he smiles and nods at her. During the ceremony, Sydney continually looks over at Adrian. At the reception, Adrian offers her a dance with him, to which she agrees. When two drunken Moroi men insult Adrian's late great-aunt, Tatiana, he becomes angry, but Sydney brings him out of his Spirit Darkness. People throughout the wedding comment that Sydney and Adrian looked like they belong together.
Sydeny askes Adrian to come with her to magic practice with Jackie, where he helps her with advice. After finding Marcus Finch, Adrian sees a bruise on Sydney and immediately attacks Marcus, saying that everything about her has to do with him. Later, Sydney is able to convince him to heal Marcus, but as a deal Adrian heals Sydney, to which she agrees.
When at a college party, in a attempt to protect young witch Lynne Titus, Adrian makes her a college t-shirt and this proceeds them sharing a passionate kiss, during which Sydney even allows him to kiss her neck, despite him being vampire, displaying her complete trust in Adrian. When she finds out the next day that Adrian has given her a hickey, she angrily tells him to never kiss her again.
Sydney invites Adrian to come with her when she is practicing magic, where she creates a Callinasta (mini dragon); they subsequently become its "parents" because the creature is loyal to whoever it sees first.
When looking through some rooms at a Bed-and-Breakfast, they lay down on the bed in the Velet Room, where Adrian reads her aura. He tells her that every time he touches her, the colour deepens, and they nearly kiss. However, they are interrputed by Alicia.
When Sydney begins to have nightmares in which she believes that Veroncia is looking for her, she is brought to a Spirit Dream with Adrian, where they play board games to pass the time.
Adrian gives Sydney advice on seducing Ian Jansonin order to get access into St. Louis to steal video footage for Marcus. After this, in a subsequent Spirit Dream, Adrian asks her to change her clothes to the outfit that she wore to St. Louis. This leads to them passionately kissing on top of a table with silverware and pieces of china; while kissing on the table they break several pieces of china. This annoys Adrian, and he changes the scenery to his bedroom, where things become hot and heavy. Sydney seems to want to have sex with Adrian, but he tells he wants to have sex with her more romantically and not in a Spirit Dream.
After noticing that Jill saw and felt everything that happened in the dream, Sydney breaks it off with Adrian, which causes an arguement between the two. Adrian becomes heartbroken when Sydney tells him that she is going with Marcus to Mexico to esape the Alchemists completely. But after a talk with Wofle, Sydney changes her mind, alongside a letter Jill gave her from Adrian that she tried to open three times. Sydney tells Marcus she can't go with him because she realised that she was in love with Adrian.
Opening the letter and finding a long series of numbers, Sydney works out that they are coordinated to Malibu where she finds Adrian at an anicent Roman and Greek museum. She admits that she loves him, after which they share another passionate kiss. They become a couple and have dinner at a foudue resturant, where they watch the sunset while holding each other. When returing to Amberwood, Adrian kisses her goodnight and promises to call her first thing in the morning. Sydney says she is walking on air and disappointed because she has to leave Adrian.
When returning back to Adrian's apartment, Sydney finds out that Adrian had been hearing his Aunt Tatiana voice, they begin to argue that Adrian needs outside help, to this Adrian denies this because he can't cut himself from Spirit. To this Sydney broke down into tears, completely overcome with fear that Adrian will eventually use too much and die or be locked up. Adrian becomes anxious that Sydney is going to break up with him because he made her cry, but Sydney tells him that she loves him and she would never break up with him. She confesses that she's scared that Adrian is eventually go insane or kill himself. After finally realizing that he did need help, though without telling Sydney, he visits a psychiatrist who gave him mood stabilizers to keep the Spirit from completely taking over.
Not long after that, Adrian and Sydney are invited to the Moroi Royal Court by Queen Lissa who needs both Adrian and Sydney's help in the blood that was taken by Olive Sinclair. On the plane trip to Court, the sexual tension had risen increbily between the two, to the put where they would secretly touch each other and exchange glances with each other throughout the flight. Once at Court, Sydney feels that she finds it more strange that she is dating a royal than a Moroi. After Adrian and Sydney have been settled into their rooms, Adrian secretly visits Sydney's room. They began to make out and Sydney decides that she may be ready to physically advance her relationship with Adrian, but can't shake the feeling that keeps stopping her. Adrian decides to take her out for breakfast, where he would point out the buildings out to Sydney. Once at breakfast bar, they are visited by three Moroi men that considered to be friends of Adrian.
In the Silver Shadows everything has changed. Sydney has been taken by the Alchemists and Adrian has now way to find out if she is okay or rescue her. Adrian's mother makes a reappearance and drags Adrian out of his drunken stupor, that he has been in ever since the night when Sydney was taken, and take him to Court. That is where he meets a temptation from his past. Fellow Spirit user, Nina Sinclair.
- According to Mead, she already planned for Adrian and Sydney to fall in love since Spirit Bound.
- Their relationship is even more forbidden than Rose and Dimitri's, since while dhampirs being together in the long run is not entirely unknown, Moroi/human relationships are completely taboo (The Keepers being one exception).
- Both Sydney and Adrian have a strained relationship with their fathers and care deeply about their mothers.
- To the fans of the Bloodlines Series, Sydney and Adrian have been named "Sydrian" which is combination of Sydney and Adrian's names.
- Sydrian came third in the Best Fictional Couples, losing to Romitri (Rose and Dimitri) in the second to last round.
- Sydney and Adrian share a "flower" in their relationship; a Morning Glory. This is strangley linked as the month for the flower morning glory is September the same month that the Bloodlines Series began.
- They are the first of the couples within both series to get married.