Tropes A to H (Big Bad, Chekhov's Gun, Deconstructed Character Archetype, Foil, Foreshadowing, Hidden Depths) | Tropes I to P | Tropes Q to Z (Red Oni, Blue Oni, Running Gag, Ship Tease, Shout-Out, Shown Their Work, Wham Episode)
Avatar: The Last Airbender has played the Red Oni, Blue Oni game plenty of times.
- Probably the most clear cut case for this in actual characters is the contrast of angry, defiant Determinator Zuko, who lives and dies with the Indy Ploy (although he is by far one of most complex reds), and the Chessmaster/Dragon Azula, who even makes blue fire (which is actually hotter). Some other notable examples of playing with red vs blue include:
- Zuko's Dream Sequence, where his Uncle Iroh is represented by a red dragon and Azula by a blue one.
- Azula's two Co-Dragons are Mai the gothic Emotionless Girl (blue) and Ty Lee the Perky Female Minion (red).
- Best friends turned enemies Avatar Roku and Firelord Sozin both had dragon companions. Roku's was red, Sozin's blue. Sozin tricks Roku, leaving him to his death.
- Zuko also plays Red Oni to every one of Team Avatar's Blue Oni's (except for Toph).
- Aang and Zuko are taught a different version of Firebending philosophy, formed, at least in part, by a red and blue dragon. Zuko is being taught to move beyond destructive motivations (his red oni background) while Aang is being taught to accept his destructive potential (against his blue oni background). Also the contrast in their facial markings. Zuko's Red Scar and Aang's Blue Tattoos.
- Zuko and Katara in general. Zuko is angry and passionate while Katara is caring and nurturing, however in the interactions between just the two of them, they switch roles. Katara is constantly angry and emotional and extremely protective of Aang and her own interests. Zuko is calm and thinks about how to deal with her. Furthermore, Katara is typically dressed in blue and Zuko in red.
- Except, of course, in each of their 'spirit' alter-egoes: the Blue Spirit and Katara's reddish Painted Lady. In that commonality, their color schemes reverse.
- During the Boiling Rock infiltration Sokka was the Blue Oni, A non bender Water Tribesmen strategist and The Leader vs Zuko's Red, a Firebending Fire Nation fighter and The Lancer.
- Zuko and Azula end up switching during the Grand Finale: Zuko, having been trained extensively in discipline and control of his strikes from Iroh, takes up the role of Blue during his final duel with Azula, while Azula embraces Red as a result of her Sanity Slippage and flies off the handle with wild and powerful strikes.
- Aang is, appropriately enough, a combination of the two. Aang normally can be both foolish and passionate (represented by his normal saffron clothes and temporary Fire Nation wardrobe change, which he later salvages to make a new set of robes). But when in his glowing blue Avatar State, Aang can become frighteningly cold and ruthless, to the point where Aang himself has nightmares about it.
- Katara and Sokka are a zigzagged example. When it comes to focusing on the mission and long-term goal, Katara tends to act on instinct and let her Chronic Hero Syndrome get the better of her whenever there's something she sees the need to attend to, while Sokka remains firmly focused on reaching the ultimate goal and generally tries not to distract himself too much with any side-quests like his sister does. However, in more general casual situations, Sokka is often a zany, eccentric goofball who consistently cracks jokes, while Katara is the mature and patient Team Mom of the group who acts as the Only Sane Woman whenever the others' vices get the better of them.
- More broadly, this applies to the Fire Nation and Water Tribe. Fire Nation are typically dressed in red (and black) compared to the Water Tribe, who are typically dressed in blue (and white or gray). Firebeinding is offensive, Waterbending is mostly defensive.
- In terms of personality this is inverted in the case of the vastly gifted motherless young daughters of important leaders on the opposing sides. Katara a passionate and somewhat impulsive Team Mom whose will sabotage her own plans to help people in need, while Azula is a calculating manipulator who has a hard time dealing with people on a personal level at all.
- The Siege of the North — the Fire Nation troops are the aggressive attackers whose deluded military leaders (General Zhao and Prince Zuko) are busy with insane schemes (to kill the Moon spirit and capture the Avatar respectively). Meanwhile, the Northern Water Tribe are defending themselves, planning to infiltrate the Fire Nation navy]] and seek help from the spirit world. The color scheme throughout those episodes fits this trope to a t — the moon and night sky become blood red when the Fire Nation Admiral Zhao begins to kill the Moon Spirit, foolishly risking the destruction of the earth in order to prevent water benders from bending, thereby making the city an easy target. The response from the Northern Water Tribe is exceptionally non-aggressive, as the princess, something of an incarnate of the Moon Spirit, sacrifices her mortal life with the aim of restoring balance to the world and enabling others to fight against Fire Nation imperialism.
- Also, the (red) Fire Nation and the (green, not blue) Earth Kingdom during the attacks and sieges of Ba Sing Se and the establishment of Fire Nation colonies, where the Fire Nation are pretty clearly the (unsustainably) aggressive party. Of course, the Earth Kingdom has the Dai Li, who dress in cooler colors and engage in more underhanded aggression, like brainwashing.
- The Legend of Korra features hero Korra and her lancer Mako who also double as the Official Couple (for the first two seasons anyway) as this trope. Their Chromatic Arrangement is the opposite of their oni; Korra, the Avatar, is a hotheaded native waterbender, and Mako is a cool and controlled firebender.
- Korra is also the brash, rough-and-rumble Red Oni to Asami's calm and elegant blue. Just like with Korra and Mako, their Chromatic Arrangement is the opposite of their oni, with Asami consistently dressing in red and Korra primarily dressing in blue. They also double as the Official Couple at the series finale.
- In Season 2, loudmouth inventor/socialite Varrick and his quiet assistant Zhu Li played very straightly. Also Desna and Eska count, Eska becomes a rather terrifying Red (matching or even more scarier than Azula), while Desna plays a submissive and somewhat more understanding Blue twin.
