|“||I'm Dylan. I'm so cool, I want to date myself, but I can't figure out how! You want to date me instead? You're so lucky!||”|
–Leo Valdez, mockingly imitating Dylan
Dylan is a Ventus (or Storm Spirit) posing as a boy who is partners with Piper on the field trip from Wilderness School to the Grand Canyon and the Grand Canyon skywalk. He later reappears to attack the Argo II and is used by Jason Grace as a source of air underwater before learning who he is. Dylan was born when Typhon was defeated by the gods in the Second Titan War.
Dylan takes Piper as a partner unwillingly at the Grand Canyon. When the storm arrives, he transforms into a Ventus, a storm spirit, son of Typhon, and pushes Leo over the side. Coach Hedge quickly jumps over the side to save him. He then blasted Jason with a bolt of lightning that only managed to knock his shoe off. He is shocked since the blast could have killed 20 men. Jason then used his sword to attack, destroying two venti that Dylan had told to attack him. When Hedge returned to the skywalk with Leo, Dylan pushed Piper down the Grand Canyon. While trying to capture at least one demigod, he attempted to capture Leo. Coach Hedge as his protector began to fight with Dylan and told Jason to save Piper. While Jason went to save Piper, Dylan flew into the clouds and escaped, taking Coach Hedge as a prisoner, who is also Piper and Leo's satyr protector.
During the fight, he said that "The mistress calls me back" and that she would destroy all demigods. When Jason is given a quest, he intended to follow Dylan and track him to where they needed to go. While Jason, Piper, and Leo are in Chicago, the group find that the city is filled with evil wind spirits, to which Leo claimed that he wanted to throw something at Dylan if he could find him. They eventually discover Medea's department store underground, where they find that Dylan brought Gleeson Hedge to her and had him placed in a cage.
When the storm spirits attack the Argo II under the direction of Kymopoleia and Polybotes, Dylan is one, described as the biggest and the meanest of the lot who wants revenge on Jason Grace. Jason's need to go underwater to confront Kymopoleia causes him to capture the biggest and meanest storm spirit who is Dylan though he doesn't realize it. Dylan is forced to provide Jason with air to breathe under water and during the battle with Polybotes, actually saves his old enemy's life by pulling him out of the way of an attack, earning him Jason's gratitude. After Polybotes is killed, Kymopoleia tells Jason that Dylan asks to be released since he helped Jason and promises not to attack him a third time. When Jason asks what she means, Kymopoleia translates that Dylan had attacked him at the Grand Canyon and wanted revenge for what happened there so he took part in the attack though he insists he never would've done it if he'd known how much more powerful Jason had become. Jason is disgusted to realize that it was Dylan who he had captured and been "breathing Dylan" while under the ocean. Kymopoleia confirms it is Dylan and Jason promises to release him which he does as soon as he and Percy return to the surface.
Dylan is very egotistical and sure of himself. While still in human form, he would constantly hit on Piper and tried to make her his partner at the Grand Canyon. Leo mentions that if Dylan could find a way to date himself, he would. When he transformed into his true form, he proved himself to be a coward in combat. He would constantly send other storm spirits to attack Jason instead of going himself, as he learned that Jason could destroy him. He also seems to hide behind Gaea, claiming that she would destroy all demigods and fled the scene shortly after. He also tells Jason through Kymopoleia that he never would've attacked Jason again had he known he'd grown so powerful and promised never to do so again. He was also described as the biggest and meanest of the storm spirits attacking the Argo II, but when ensnared by Jason, he was docile. Despite his cowardice, Dylan showed a moment of bravery when he saved Jason's life from Polybotes even though he didn't have to, earning him Jason's gratitude before he learned exactly who the storm spirit he'd been using for air was. He was shown to hold grudges as he participated in the attack on the Argo II for revenge on Jason according to what Kymopoleia communicated for him. However, he let go of this grudge due to fear of Jason when he kidnapped him to go beneath the sea.
In human form, he is described as having a smile so bright that they should come with a warning label ("WARNING: Do not look at teeth directly, blindness may occur"), a Dallas Cowboy's football jersey, and dark Superman style hair.
In Ventus form, he is said to look similar, except no jersey and he is pale with eyes sparking with electricity, has black smoky wings, and he is surrounded by strong winds. His form is composed of swirling dark vapor and has said to look like an evil angel to Jason.
- Electrokinesis: As a Ventus, he can control and manipulate lightning and electricity.
- He can generate huge bolts and arcs of static electricity from his body.
- He can send strong electrical shocks through contact on others.
- He can summon lightning bolts from the sky.
- Aerokinesis: As a Ventus, he can control and manipulate the air.
- He can control and generate very powerful winds and air currents.
- He can be used by a someone to provide air and protection under water.
- He can fly at the speed of wind.
- He is able to become intangible.
- Dylan was on Coach Hedge's baseball team all season, though Gleeson could not smell him.
- Dylan and Jason Grace have a complicated relationship: at first the two are enemies and Dylan holds a grudge against Jason for this until the Blood of Olympus where he attacks the Argo II and Jason for revenge. Ironically this gets him ensnared by Jason and cements his fear of the demigod, stating he'd never have attacked him again if he knew Jason had grown so strong and never will again if released, apparently fearing Jason would enslave him. Despite this, he saved Jason's life in battle when he didn't have to and Jason was grateful to him, planning to get him an air freshener (though he didn't know if Dylan would like or appreciate it) right up until he learned exactly who Dylan was at which point he was disgusted.