Mateo Mandelson and the Secret of the Sigils is a Web Serial Novel by Idea Dump centered around the titular Mateo Mandelson and his battles against the Branded, a group of six men with superpowers.
Mateo Mandelson and the Secret of the Sigils provides examples of the following tropes:
- Abusive Parents: Mr. and Mrs. Modeston treat Oliver pretty terribly, mostly because they believe the Collective made him wrong. It's subverted with both Aldrich and Vita, however, who were the ideal parents to Mateo before the Collective got to them. Cassius also subverts it, ironically enough, as he's shown to be quite the fatherly figure towards the children he rescued from Brutus's laboratory.
- Adaptive Ability: The power of Longinus's Sigil. It's the primary reason why he's so hard to kill, as his body and mind instantly adapt to anything that's done harm to him at least once.
- Aerith and Bob: All over the place, but special mention goes to the first names of the main characters: Mateo, Molly, Killian, Oliver and... Perseus.
- It's justified, though, as Perseus is literally centuries old.
- Aerosol Flamethrower: Guido's go-to means of offense when he doesn't have enough energy to Hulk Out.
- All Up to You: Mateo is eventually forced to take the initiative and lead the fight against the Collective as anyone else who could've winds up either dead or missing as the fight grows more chaotic.
- Always a Bigger Fish: Longinus is miles more powerful than Cassius could ever hope to be, and once he makes his presence known, he tears through Nocturne HQ, killing dozens of soldiers and effortlessly beats Cassius to a bloody pulp.
- Longinus status as an Invincible Villain and Karma Houdini comes to an end once the Collective shows up, though. Oh beats him so bad that he's reduced to a wriggling pile of guts.
- Ambiguous Innocence: Guido, full stop. He's the worst underling Cassius's got, but he doesn't necessarily do what he does out of devotion to Cassius, let alone malice. Rather, he feels that the law doesn't apply to him since he's part of a criminal organization, and he does what he does because he finds it fun.
- And I Must Scream: If her reaction to being freed's anything to do by, Vita spending the past 20 years under Andromeda's control and forced to stand in one spot whilst raw energy was being channeled through her body was not a pleasant experience.
- Anti-Hero: Oliver Modeston, especially after he defects from Mateo's group; he's still a good guy, but his methods of doing good are far from ethical.
- Anyone Can Die: Mateo Mandelson's world is a dangerous place. Almost all the Branded play for keeps, and any member of the Collective is sure to have a high body count when they show up.
- Appeal to Force: Longinus does this all the time, thanks to what his Sigil can do.
- Arc Villain: Cassius and Nocturne at the beginning of the story, then Aurelius and the Brotherhood after Rho appears slaughters all Cassius's men, then Longinus and his Mutant Army after Aldrich steals the Sigils of all the Brotherhood's members, and finally Andromeda and her Collective after they decimate Longinus's army and Alpha beats Longinus to a bloody pulp.
- Armor Is Useless: Even though it's imbued with energy from Cassius's Sigil, the armor the foot soldiers of Nocturne wear do virtually nothing to protect them from the attacks of Branded who're even stronger.
- Astonishingly Appropriate Appearance: Averted for practically all the Branded, as they all were just regular people before they got their powers, thus they have appearances unrelated to them. The only Branded who plays this straight is Thornton; he has spiky hair and a mouthful of pointy teeth, and wears a leather jacket covered in spikes, which fits his ability to shoot spikes out of his body.
- Attack! Attack... Retreat! Retreat!: A hoard of Nocture foot soldiers charge at Vii in an attempt to kill her while she's powered down. Then she starts laughing. Then she inexplicably grows into a deformed monster. Then the soldiers run for their lives.
- Badass Normal: Killian Mc Cormick has no Sigil or supernatural powers to speak of, but can still hold his own in a fight.
- The Bad Guys Win: Cassius eventually acquires the Sigils of all his fellow Branded—save for Mateo, Perseus, Aldrich, Longinus and himself—and uses their combined power to break a hole into the Collective's realm to see Andromeda. That, and he finds out he was right about Vita never dying and being kept under the Collective's control. Vita (being controlled by Andromeda) casts him out of the Collective's realm shortly after, but, while that breaks him pretty badly, he was still able to confirm something that's been bugging him for decades. Not to mention the majority of Branded are dead and gone.
- Big Bad: Andromeda, being the one who created the Sigils in the first place.