History Main / YinYangBomb

** In addition, this trope is the secret of the immortality of the BigBad of the first book. The first book reveals two [[FunctionalMagic magic systems]]: Allomancy, which works by ingesting various metals and consuming them to get temporary power-ups, and Feruchemy, which works by saving up a person's own attributes like strength or health in metals and consuming them later in an EquivalentExchange. Both are inborn. Allomancers are generally more dominant in society and more oriented towards combat, but we're told that Feruchemy has its own strengths and weaknesses and can do things that Allomancy can't. In the end, [[spoiler: we learn that if someone is both an Allomancer and Feruchemist, storing up attributes in metal then burning the metal gives them back ten times what they lost; doing this with youth and health makes them effectively immortal]].

** ''VideoGame/DevilMayCry2'' takes place on the island of Vie de Marli. In the Japanese release, the island is referred to as ''Sei to ma no tokeau shima'' ("The island where Holy and Evil merge").

*** [[spoiler: Savathun herself becomes this during "The Witch Queen". After she is freed from her worm, she dies, but is later resurrected by the Traveler, being reborn with the power of the Light. Her new army consists of similarly revived Hive Guardians like herself, called the Lucent Brood. Despite their new Light-based powers, they retain many of the elements from their previous lives drawing upon the Darkness. They continue using their old Hive weapons, weapons made using Hive magic, which draws from Darkness, and Savathun herself continued using Hive magic for her own plans.]]

*** [[spoiler: The Raid for the Lightfall expansion, "Root Of Nightmares", revolves around Nezarec, one of the Disciples of the Witness, who was reborn as this trope. Once a being of immense Dark power, after he was killed by Savathun, his body was buried in the Witness's Pyramid. At the start of the "Lightfall" storyline, the Traveler launched a beam of immense Light energy to attack that Pyramid. The beam made contact with Nezarec's body, and the Traveler's innate terraforming power caused Nezarec to re resurrected, only now with both Light and Dark energy at his disposal. The boss fight against him in the Raid involves turning the combined forces against him to break his defenses.]]

*** [[spoiler: The storyline going forward has Guardians gain further Darkness abilities to combat the new more powerful threats emerging. In "The Witch Queen", Guardians unlock the power of "Deepsight", a Dark-based power than enables them to look into the past and see through the illusions of Savathun's Throne World.]]

** [[spoiler: In the sequel, ''VideoGame/Destiny2'', beginning in the "Beyond Light" storyline and going forward, Guardians themselves become this, gaining Darkness-based abilities in addition to their usual Light-based ones. The Exo Stranger, revealed to be Elizabeth "Elsie" Bray, helps the Guardians to begin training with Darkness powers. According to Elsie, Darkness exists in every living being just like the Light. In the timeline she comes from, Guardians turned to the Darkness in desperation and became corrupted by it. In "Beyond Light", Elsie seeks to prevent history from repeating by helping Guardians to master the subclass Stasis, granted from the Europan Pyramid, which takes form as the power of ice.]]

** [[spoiler: In the sequel, ''VideoGame/{{Destiny2}}'', beginning in the "Beyond Light" storyline and going forward, Guardians themselves become this, gaining Darkness-based abilities in addition to their usual Light-based ones. The Exo Stranger, revealed to be Elizabeth "Elsie" Bray, helps the Guardians to begin training with Darkness powers. According to Elsie, Darkness exists in every living being just like the Light. In the timeline she comes from, Guardians turned to the Darkness in desperation and became corrupted by it. In "Beyond Light", Elsie seeks to prevent history from repeating by helping Guardians to master the subclass Stasis, granted from the Europan Pyramid, which takes form as the power of ice.]]

* [[SpaceElves The Awoken]] from ''VideoGame/{{Destiny}}'' [[spoiler:were created by a Yin-Yang Bomb; they were human colonists trying to flee the solar system during [[ApocalypseHow the Collapse]], but they weren't fast enough and got caught in the crossfire between [[CrystalDragonJesus the Traveler]] and [[EldritchAbomination Darkness]]. The Light and Dark magic bombarding their ship combined to create [[UsefulNotes/BlackHoles a singularity]] that sucked them into [[{{Arcadia}} a newly-created pocket dimension]] and mutated them into the ethereal [[{{Transhuman}} Transhumans]] they are now.]] This is why they wield powers no other beings possess; they're a strange sort of middle ground between the Light and the Dark.

*** The player character is able to tap into this generally speaking, using jobs that heavily use light magic (eg. White Mage or Paladin) and dark magic (eg. Black Mage or Dark Knight). Symbolically they achieve this during the ''Shadowbringers'' expansion: having been become famed as the Warrior of Light in their efforts to fight back against the darkness brought by the Ascians, they journey to a parallel world which is about to be consumed by forces of light that have been unleashed by Ascians; thus they take up the new mantle of the Warrior of Darkness in order to bring back the light and balance to the world. It's not uncommon, post-''Shadowbringers'', for players to refer to their character as the Warrior of Light ''and'' Darkness.

* ''LightNovel/FixedDamage'': While most people think [Light] and [Darkness] attributes are antithetical to each other and will mutually annihilate, that's wrong. They may be mutually antithetical, but they feed off of and strengthen each other when they clash, and they have a tendency to fuse into [Chaos] which precious little can stand against. Chrome and Yuno learn this by accident when they clash both with each other and with other wielders of their respective opposite element.

* An issue of ''ComicBook/AstroCity'' subverts this, where ChromeChampion Steeljack faces off against a FireAndIceDuo of thugs. They blast him simultaneously with both their powers... but as it turns out, while the ice guy could have frozen him solid and the fire guy could have melted him to slag, both together just cancels out their temperatures and leaves him with nothing worse than a ruined shirt. Steeljack mentally notes that if they'd alternated their attacks instead, they might have seriously hurt him.

** Elise from ''VideoGame/TalesOfXillia'' combines dark based offensive magic with light based healing. She and Milla can use the aptly named Chaotic Fuser [[CombinationAttack link attack]], which forms a sphere of light and darkness around the victim that eventually explodes.

** An interesting [[BonusBoss superboss]] example comes into play in ''VideoGame/FinalFantasyXII'', with the [[DarkIsEvil Hell Wyrm]] boss. Despite it being called the [[{{Satan}} King of Hell]] in the bestiary, it's strongest attack is '''Holy''' elemental. This is also considering this boss has access to darker abilities, such as Darkga.

** In addition, this trope is the secret of the immortality of the BigBad of the first book. The first book reveals two [[FunctionalMagic magic systems]]: Allomancy, which works by ingesting various metals and consuming them to get temporary power-ups, and Feruchemy, which works by saving up a person's own attributes like strength or health in metals and consuming them later in an EquivalentExchange. Both are {{Inherent Gift}}s. Allomancers are generally more dominant in society and more oriented towards combat, but we're told that Feruchemy has its own strengths and weaknesses and can do things that Allomancy can't. In the end, [[spoiler: we learn that if someone is both an Allomancer and Feruchemist, storing up attributes in metal then burning the metal gives them back ten times what they lost; doing this with youth and health makes them effectively immortal]].

** With ''VideoGame/{{Hearthstone}}'' being based on ''Warcraft'', it is only fitting that the Priest class in that game continues that tradition, having both Light and Shadow-based spells in its arsenal.

** Natsu defeats [[spoiler:[[EvilCounterpart Zancrow]] in this manner; by canceling his own magic, Natsu gains the ability to eat Zancrow's flames. Then he combines his red dragon slayer flames with black god-slayer flames for a truly brilliant finishing move]].

** In ''VideoGame/KingdomHeartsIII'', the Oathkeeper and Oblivion keychains (introduced in an update) let Sora access Light Form and Dark Form. From either Formchange, he can then enter Double Form, which visually incorporates elements of both prior forms and utilizes all kinds of light-and-darkness combo attacks, DualWielding Oathkeeper and Oblivion in a similar manner to Roxas.

** In ''VideoGame/KingdomHeartsIII'', the Oathkeeper and Oblivion keychains (introduced in an update) let Sora access Light Form and Dark Form. Once he's in either Formchange, however, he can enter Double Form, which visually incorporates elements of both prior forms and utilizes all kinds of light-and-darkness combo attacks, DualWielding Oathkeeper and Oblivion in a similar manner to Roxas.

** The Red Mage job of ''VideoGame/FinalFantasyXIV'' functions a bit like this. In the XIV universe Red magic is achieved by using the body's own natural aether amplified by their crystal focuses to cast both white and black magics and storing the resulting aether within. When in balance the two combine to form red magic, which is delivered by melee attacks and amplified by their swords. The basic idea being that the Red Mage does not have to drain aether from the land to cast.

* ''Manga/HighSchoolDXD'' has Kiba, whose Balance Breaker is a sword that's comprised of the powers of both light and darkness.

* In ''Manga/CardCaptorSakura'', the two most powerful cards, the Light and the Dark, are always used together. Comes full circle in the [[Anime/CardCaptorSakura final movie]]. [[spoiler:The Nothing consumes the nameless card to become the Hope.]]

* ''LightNovel/ACertainMagicalIndex'':

* ''LightNovel/{{Slayers}}'':

* ''LightNovel/HighschoolDXD'':

* In ''VideoGame/AzureStrikerGunvolt3'', one of the [[AmazonBrigade ATEMS Knights]] is Prado "the Dual Knight", so named because her [[PsychicPowers Septima]] "Hot & Cold" grants her the ability to generate fire and ice from different sides of her body and use them in tandem, with her transformed state has her armor colored red on one side and blue on the other. Notably, this is a very unique ability as previous Septimas, while capable of branching into various powersets, usually have the powers be closely related rather than such an obvious duality, to the point the heroes assume seeing the elemental carnage she left in the stage that a pair of Adepts had done it rather than just one. It's for this reason she considers herself a BornWinner.