Ryan Noble is Erin's brother and former vampire slayer. At the beginning of the series he is turning into a vampire after been bitten by Ingrid (his blood gives her blood poisoning). Throughout the beginning of series 3, Erin tries her best to find a cure for Ryan.
Season 3In episode two it is revealed that Erin was hiding Ryan in her car boot whilst she was staying at the Draculas' House, she gives him some sort of serum from the Slayer's Guild to drink which probably helps to keep the thirst at bay. After drinking the last vial of it, Ryan states that the two of them are on their own now, saying they 'cannot exactly go back and ask for more'. The Slayer's Guild would kill him if they knew he was a Half Fang, Ryan says that he is running out of time and asks Erin to stake him when the time comes.
Erin refuses to give up on her brother and promises that she will find a cure for him. She believes that staking Ingrid will free her brother from the curse and explains to Ryan that she has an opportunity to get close to Ingrid after Vlad invited her to stay at their house. Ryan jokes that Erin can't live with vampires because she is vegetarian. Erin reassures him that she will not fail and tells Ryan to rest while she puts her plan into action.
Later on in episode 2 she goes back to check on Ryan. She brings him the bad news that she wasn't able to slay Ingrid despite the fact that Ingrid was weak and at her mercy. Erin apologises and says she doesn't know why she couldn't kill her, Ryan comforts her and says the reason why is that his sister is not a killer.
He then says goodbye to Erin explaining that the transformation is occurring fast and that he is now too dangerous to be around and he heads off into the night.
He reappears in Episode 9 to check on Erin's progress on finding a cure. Erin informs him that she still hasn't been successful. Ryan isn't disappointed with her as he knows she's trying her hardest but is sad at the fact that time is rapidly running out for him and that hardly any of his human side remains.In episode 10 the Van Helsings find Ryan sleeping in a coffin during a 'stake out', just as he is about to be slain Ryan explains that he can give them information about the Draculas. When Erin confronts the Van Helsings in the same episode they tell her that they are unsure of Ryan's current location. (Though it is later revealed in episode 12 that they were keeping him prisoner in their Slayer HQ).
In episode 12, Erin is forced to slay her brother in order to prove her loyalties to the Van Helsings, however she tricks them and helps her brother escape. Erin is horrified when Ryan tells her that he is now fully transformed into a vampire and loyal to his maker (Ingrid), he then heads off to be with her. Ryan arrives at the Draculas' House and tells Ingrid he wants to join her army, he warns her about the Slayers' plan to destroy them all that night using a secret weapon. When the Van Helsings arrive at the house, they fire a UV ray at Ingrid but Ryan saves her by deflecting the attack by using a wooden plaque with silver medals on it.
After telling Vlad that she intends to kill him and thus take over as ruler, she leaves with her army of vampire girls and Ryan joins them.
He appeared in episode 13 in which Ingrid orders him to steal the Praedictum Impaver and a load of weapons for her army. Whilst Ryan is sneaking around trying to grab the book, he witnesses Betrand kidnap his sister. Betrand ties Erin up to wall and drops the Praedictum Impaver at her feet and intends to use her blood to finish filling up the text in the book. However the two of them begin arguing and Betrand leaves the room, Ryan comes out of hiding and tells Erin that he will free her but only when he has successfully helped Ingrid achieve her ultimate goal. Erin tells him that Ingrid cannot be trusted and begs Ryan not to lower himself and help Ingrid. This annoys him as he is extremely loyal to Ingrid and so does not like it when people speak ill of her. Ryan gags Erin to shut her up and leaves with the Praedictum Impaver. Ingrid's 'vampette' army kidnap Renfield and attempt to use his blood to fill in the missing pages in the book but it doesn't work. When Ingrid questions why and asks what is it that Erin has that he does not, Ryan jokes "Cleanliness". From Ryan speaking, Ingrid guesses that Slayer's blood is the key (because he is Erin's brother and a former vampire hunter himself and so this theory instantly clicks in Ingrid's brain). She takes a bottle of slayer's blood that Renfield carries for the Count and pours it into the book but there isn't enough of it, at that moment Betrand appears with some old friends and the two groups quarrel over the book. Vlad and Erin appear and Vlad uses his powers to confiscate the Praedictum Impaver and Erin cuts her finger and uses her blood to fill in the last page. The book ressurects one of the first vampires, Sethius, who wishes to create hell on earth by draining all the breathers dry and then watch starving vampires destroy each other in the madness. Ingrid and Betrand grow cold feet about allying themselves with Sethius when they see how insane he truly is and agree to help Vlad destroy him. Ryan helps the others to put this plan into motion and together they all manage to kill him.
In the first episode of Series 4, the Vampire instinct causing newly-bitten vampires to be loyal to their maker has started to wear off, and Ryan abandons his loyalty to Ingrid. He dislikes the 'ceasefire' that Vlad and Jonathan Van Helsing have put into place, and forms an alliance with a vampire named Malik to end it. In series 4 episode 4, Ryan was slain with garlic tipped thorns after winning a quiz against Malik. Later in episode 5, a shapeshifter pretends to be his ghost to trick Erin.