After Viggo is betrayed by Krogan and Johann, he seeks out Hiccup to get his revenge. Naturally, Hiccup trusts Viggo about as much as he trusts Johann at this point, so Viggo resorts to his usual tactics to get Hiccup's aid.
- Annoying Arrows: Subverted. While the numerous arrows in his back don't stop Viggo from walking or talking, he makes it clear that he won't live past the day.
- Artistic License Biology: At the very least, Viggo's hand should have been burnt to a crisp when the dagger he was holding was struck by the Skrill's lightning bolt.
- Call-Forward: Viggo reveals that he's copied Hiccup's Inferno sword and made his own adjustments, with a retractable blade and a release mechanism for Zippleback gas. It clearly resembles the completed version of Inferno that Hiccup possesses in the second film, implying that Hiccup's final design was inspired by Viggo and was a tribute to his sacrifice.
- Chekhov's Gunman: After Hiccup and Toothless are quickly captured by Johann when escaping from the cave, the twins' record-setting comes in handy for Big Damn Heroes.
- Crying Wolf: Hiccup is understandably skeptical of Viggo's HeelFace Turn after the last time he tried this.
- Deliberate Values Dissonance: To a real Viking in the ancient Nordic world, dying in battle would be the happiest ending he could ask for.
- Flaming Sword: Viggo now owns his own version of Inferno, complete with a rear hilt mounted gas release system, presumably an idea Hiccup borrows in his later versions. The pair even fight using their fire swords!
- Viggo reveals to Hiccup that Krogan does not work for Johann, but a "mysterious buyer from the north."
- Viggo also warns Hiccup, "You are too good, too pure, too innocent, which will get you or someone you love killed." He seems to be predicting the events of the second film, where Hiccup's problems are at least partially due to his Wide-Eyed Idealist-insistence that he can convince Drago to change.
- Friendship Trinket: Viggo gives Hiccup a Maces and Talons piece to remember him by before his Heroic Sacrifice.
- HeelFace Revolving Door: The episode leaves it until the last moments to reveal his true allegiance, and does a good show of having Viggo flit between the two very easily.
- HeelFace Turn: Viggo, after being left for dead and at the mercy of a Monstrous Nightmare. Not only does the near death experience turn him from the Hunters, but he starts to respect dragons far more than he ever did before.
- I Have to Wash My Hair: Snotlout claims he has better things to do than be a witness to the Twin's record breaking. When Ruffnut asks for a specific thing he is doing, he runs off without answering.
- I Owe You My Life: Viggo's opinion of dragons improve immensely after a Monstrous Nightmare saves him from the crashing caverns Krogan and Johann left him in.
- Improvised Lightning Rod: Viggo uses a dagger to attract a lightning bolt, in-turn getting the attention of a Skrill.
- Leave Me Alone!: Hiccup and Astrid just can't catch a break, now can they?Hiccup: Finally, some alone time.
Astrid: No distractions, no interr—
Tuffnut: Incoming! [Ruffnut, Tuffnut, Barf and Belch crash into their picnic and destroy everything.]
Hiccup: Oh, for Thor's sakes, what are you guys—
Ruffnut: Nope, not long enough.
Tuffnut: What about width?
Ruffnut: Sorry, bro. Width and length, both too small.
Tuffnut: Oh, come on!
- Mortal Wound Reveal: Viggo stumbles into Johann's chamber to meet Hiccup. After a short conversation, Viggo turns to the side and reveals he has numerous arrows stuck in his back.
- Motivational Lie: Viggo claims to have given Toothless a slow-acting poison so Hiccup will have to go along with his plan to get the antidote. At the end, he admits he lied about the poisonous effects of the flower.
- Poison-and-Cure Gambit: Subverted. Viggo uses this to force Hiccup into cooperation, but the poisoning never actually happened.
- Redemption Equals Death: After performing his HeelFace Turn, Viggo takes a half dozen arrows to the back and goes out fighting his former allies, with the aid of a Skrill he tamed.
- Rule of Symbolism: Hiccup leaves the Maces and Talons game piece Viggo gave him turned on its side on the board, leaving a few interpretations open:
- "The traitor (always) dies at the end.": Though Johann and Krogan did the real work of turning on Viggo, from their view Viggo already betrayed their cause because of his feelings for Hiccup and his narrow focus on the game.
- The real-life symbolism of overturned game pieces on a board often brings home their "sacrifice" from the other "enemy" side (especially if they have checkmated). Aside from the obvious sacrifice on Viggo's part, it also brings the series-long "game" between Viggo and Hiccup to a close on bittersweet terms.
- Schmuck Bait: When Hiccup receives a letter from his father saying come alone to where a new dragon eye lens might be, it does not take the gang very long to smell a trap waiting for him. While Hiccup does not exactly trust it himself, he decides that the risk that it is Stoick with a new lens was worth it.
- Self-Serving Memory: Krogan rattles off a list of reasons Viggo should hate Hiccup... except Hiccup's not responsible for any of the events Krogan accuses him of:
- "He scarred your face..." — This, of course, is entirely Viggo's own fault.
- "... destroyed your brother..." — Ryker was eaten by the Submaripper. If any human can take credit for it, it's Viggo for bringing in the Submaripper; it certainly wasn't Hiccup's idea.
- "... and decimated your empire!" — If anyone can be held responsible for that, it's Ryker, who took over the hunters and began attacking the archipelago with the Shellfire; all Hiccup and the riders did was defend their victims, with Viggo's help.
- "Shaggy Dog" Story: The most tragic part of the story is that no one gains anything. Viggo's and Hiccup's goal of getting the Dragon Eye and lenses and ruining Johann's and Krogan's partnership completely fails. The only thing Viggo's sacrifice accomplishes is saving Hiccup, but he would never have been in danger in the first place if it hadn't been for Viggo. Aside from inspiration for improving Inferno, Hiccup and the riders are no better off than they were before Viggo's death.
- Whole Plot Reference: Viggo's plan is identical to Thor's and Loki's in Thor: The Dark World. Viggo even quotes Loki when he "betrays" Hiccup by saying, "I've brought you a gift."
- Worthy Opponent: The riders all regard Viggo as this when Hiccup tells them about what happened to him.
- You're Insane!: This is Hiccup's reaction when he learns that Viggo plans to tame a Skrill.