Over the course of the series, there have been several frightening elements.
- Briefly Dai sees his adopted father figure, Brass struggle from going evil again and attacking him due to Hadlar's influence. Luckily, Avan creates a barrier to negate the adverse effects just in time.
- Avan transforming into an intimidating dragon in order to test Dai.
- Hadlar in his initial introduction, proves to be the fearsome enemy from years prior by outmatching Avan who had managed to kill him before, force himself into Avan's barrier and even survive Avan's Heroic Sacrifice attempt. And what was worse was that he isn't above killing the young Dai and Popp for being potential threats.
- This is then worse when Hadlar reveals that there's an even more powerful force behind him named Vearn, serving as Nightmare Fuel in-universe with that single astonishing revelation.
- Zaboera convincing Crocodine to use the captured Brass against Dai, forcing Dai to face off his adopted father figure due to the latter being under Hadlar's influence. Dai is understandably freaking out from having his adopted father figure act in an uncharacteristic and dangerous manner since the island when Hadlar had been resurrected and it is now doubled now that he's being used as an enemy against Dai.
- What a Hadlar-controlled Brass does is equally unsettling, making the soldiers hallucinate their comrades as skeletal monsters and forcing them to kill each other. And then he attacks Dai ruthlessly as the boy is unable to fight back with brutal force.
- Baran's entire existence. He was ostracized from humanity due to his Dragon Knight heritage after finally settling down following his vanquishing Velther and it resulted in his wife's death- cementing his hatred of humanity. He would later show up to Dai and attempt to brainwash him into agreeing with his methods and fight his own friends.
- Vearn decides to have his own already menacing base become a massive mechanized robot to attack the world leaders with its overwhelming size and might.
- Baran's own Dragon Knight form becoming a winged, draconic, demonic humanoid to fight Dai and the heroes.
- Zaebora's son briefly absorbing Dai into his hideous Hyper-Demon form.
- Vearn demonstrating why he's a menacing enemy to be defeated by sending out a seemingly weak flicker of flame that explodes into a column of flames to incinerate Baran's corpse, starting off the hopelessly outclassed fight the heroes would first have with Vearn as well as establishing his vastly superior powers and cruelty.
- Zaebora undergoing a Hyper-Demon transformation by absorbing all of his subordinates to become become a skull faced demonic monster.
- Myst-Vearn's true form of a creepy looking, sentient shadow who can possess others in order to fight physically as he demonstrates with Maam.
- It also doesn't help that the anime clarifies that this is a painful experience, and when he holds people, it nearly looks like Naughty Tentacles.
- As the final fight with Vearn seemingly ends in Velther's petrified visage appearing to Vearn, commenting on how the former won the wager on who would conquer the human world first. It's this moment that cements how insignificant the heroes were to Vearn at this moment, it wasn't a personal battle, but rather a long planned out game of chess between two ancient evil beings that casually used everyone as pawns in their game.
- The psychological horror of Hyunckel not only being a member of the Dark Army, who had planned to kill Avan even before he was a member, but also the fact that the reason was that Avan had apparently killed Hyunckel's father figure due to his role as the hero and the father being on the enemy's side. No wonder Dai was conflicted about the issue initially.
- For that matter, Flazzard lacking any scruple or compunction towards mutilating or inflicting atrocious harm on his foes.
- He is half made of rocks on permanent fire, and he grabs one of the Papnica Troika with his hand.
- In the manga and the 91 anime, he outright flares up to disfigure her, for no other reason than to basically spit in the face of all that is decency and morale.
- Then in order to spite Dai and ensure he doesn't run away, he goes and inflicts a Human Popsicle treatment to Leona with the added bonus she will be drained of her life force in a matter of two days.
- This is after having created a barrier that causes a Field Power Effect sealing effectively all magic and reducing his foes strength to a fifth. When you think of all the trouble the heroes had dealing with that, you realize the untold amount of harm he has inflicted on the kingdoms he has conquered.
- And THEN Hadlar points out that Flazzard is born from him, a literal manifestation of his ambition and drive for greatness. It gives insight into how twisted Hadlar was, especially when you compare Flazzard to the MUCH MORE honorable Orichalcum Honor Guard.
- He is half made of rocks on permanent fire, and he grabs one of the Papnica Troika with his hand.
- Dai realizing he has to use his full power, the two Dragon crests, which will impart upon him such bloodlust he will turn Ax-Crazy and Not Himself, and might turn him into a One-Winged Angel like his father Baran. He himself is very aware of that, and remained Willfully Weak to not lose his humanity. The extremely brutal beatdown he inflicts upon Vearn with what is just focused Unstoppable Rage when liberating his full power proves he was right. Vearn himself freaks out.
- Maam's Dull Eyes of Unhappiness when she suddenly remembers Popp is facing Sigma all alone and thinks about what happened if the Knight Orichalcum warrior used his Mirror of Shahal against the Sage's Medroa. It is so sudden because there's no fading on her eyes becoming dull, no blink, it just turns into a flat brown devoid of all light
◊ out of nowhere!
