Author's note: This is my first fanfic that I've written. It's a crossover between How To Train Your Dragon and Zelda Breath Of The Wild/Age Of Calamity. I'll reveal details of both timelines of both realities as the story advances, but to start, Hiccup and Astrid are having the chat while overlooking Berk at sunset from httyd 3 when they are transported to Hyrule. The Zelda timeline is in the Age of Calamity timeline, around 4 years after the end of the game so that Hiccup, Astrid, Zelda, and Link are around similar ages. Anyways with some context provided, on with the story!
Chapter 1-Arrival
"Ow," cries Hiccup Haddock as his girlfriend twists his arm. Astrid Hofferson giggles at the success of the move that she can always use to get Hiccup to reluctantly agree with her. He reaches out towards Astrid calling out. "Come here you." Toothless and Stormfly stop their playtime to watch their riders play fighting.
As Astrid raises her arm to punch Hiccup, a strange sound suddenly fills the air. Hiccup notices a faint blue circle appearing around himself, Astrid, and their dragons. As he reaches for Inferno, strapped to his right hip, the circle becomes more visible, glowing whitish blue along with weird runes appearing around the perimeter. Getting to their feet, Hiccup and Astrid notice the ground inside the circle turning white, energy swirling around the circle. Both of them immediately go to their dragons and mount up. Astrid is on Stormfly and Hiccup is halfway through mounting Toothless when the white ground inside the circle disappears.
Suddenly all four of them are falling into a tunnel of white and blue energy, the weird runes from earlier circling around them. As soon as they enter the tunnel, they exit it. Both Hiccup and Toothless suddenly feel wind rushing against their bodies at high speeds. As his vision clears, Hiccup realizes that they are high in the air, free falling towards snowy mountains far below them.
A metallic snapping sound causes Hiccup to look at his prosthetic foot, seeing Toothless grabbing it to keep Hiccup close. With horror, Hiccup realizes that the snapping sound was the metal foot breaking, taking the ability to operate Toothless's tail fin with it. Unable to fly on Toothless or use his flight suit, since that is built into his Night Fury armor, which is currently in Hiccup's house, Hiccup looks around for his only possible savior: Stormfly. A squawk alerts Hiccup to the Nadder's presence, above him, the beautiful blue dragon struggling to get a good flying position.
Astrid lets out a sigh of relief as she gets Stormfly to level out and fly steadily. Her relief is short-lived when a loud "Astrid!" catches her attention.
Looking down, she sees Hiccup flailing in the air alongside Toothless, the distant ground slowly getting closer. As Astrid looks at Hiccup, something catches her eye, below them but above the ground, Astrid sees a strange structure. It almost looks like a giant bird, but made of some stone-like material.
Another yell from Hiccup alerts Astrid to the fact that Hiccup and Toothless can't fly. Mustering her volume, Astrid yells at Hiccup. "Get onto Toothless's saddle, I'll Stormfly grab Toothless and carry you to the ground." Hiccup manages to reply by saying "Try aiming for that giant bird, it looks sturdy enough for the four of us!" Astrid relays her instructions to Stormfly and the Nadder squawks in agreement.
Looking over at Toothless, Astrid sees a patch of brown and black over the Night Fury's neck, Hiccup in the saddle. "Stormfly, now!" Stormfly dives towards the falling black dragon and grasps the dragon's sides with her talons. Astrid lets out a startled cry as the sudden extra weight of a walking fishbone and stubborn Night Fury cause Stormfly to drop suddenly, losing around ten feet of air. "This is going to be a rough landing Hiccup!" Astrid yells over the wind as the giant bird grows closer.
Hiccup holds on to Toothless for dear life as Stormfly works to slow their descent towards the giant stone bird rushing up towards them. His mind realizes that Stormfly will have to drop Toothless so she can land safely, meaning Toothless will have to roll once they land to avoid injury.
Looking up at Astrid, Hiccup calls up. "You're going to have to drop me and Toothless so that Stormfly can land safely." Panic appears on Astrid's face as she replies. "You can't be serious? That will injure both you and Toothless!" Sighing despite the life or death situation, Hiccups calls back. "Toothless will wrap me in his wings and roll when you drop us to lose momentum. He's done this with me before and it works!"
"Fine, I'll agree to it." comes Astrid's reply, uncertainty clouding her voice. Hiccup nods and turns back, startling at seeing how close the giant bird is, calculating the moment to have Astrid drop him.
Astrid gets more worried the closer they get to the giant bird, nervous about Hiccup's plan to protect himself. As Stormfly descends to around fifteen feet above the colossal stone bird, Astrid hears Hiccup yelling "Now!" Recognizing this as Hiccup's signal to be released, she tells Stormfly. "Stormfly, drop him!" With a chirp for a reply, Stormfly releases her hold on Toothless and immediately her descending slows. Astrid sees Hiccup climbing to the underside of Toothless's neck and the Night Fury closing his wings around Hiccup. A second later, they hit the stone bird on the left wing, at an angle and roll towards the center of the bird's back.
After Toothless closed his wings around Hiccup, all he can see is black, but as he feels Toothless crashing, Hiccup finds himself being tossed around, inside the protective wrap of the Night Fury. After several seconds of rolling, Hiccup feels Toothless slow to a stop.
As the dragon opens his wings, Hiccup sees Stormfly landing and Astrid jumping off her back, running towards Hiccup. She grabs Hiccup and pulls him into a tight embrace. Hiccup returns the gesture, and they don't move for a moment.
Toothless and Stormfly watch in relief, seeing that their riders are okay. Astrid releases her embrace around Hiccup, and he looks at their surroundings. His only words are "Where are we?"