Rinji Kyoso is an rival-type character in a Digimon Frontier Fanfiction planned by Taylor Gorrell. He holds the Spirits of Combined Power, artificial Warrior Spirits created from combined data from all ten Legendary Warriors. Despite this, he is an antagonistic character who only wishes to defeat the Legendary Warriors. His last name comes from "Rivalry (競争 Kyōsō?)."
Rinji is a fourteen-year-old boy of average height, with black hair with a dyed white bang and green eyes. His attire consists of a red shirt with the kanji for "Power (力 Chikara?)" on it in blue, a gray jacket similar to that worn by Takuya, dark green pants with a chain hanging from one pocket, and dark blue shoes.
In terms of personality, Rinji is not a very friendly person. In the Japanese version (if there was one), his speech pattern is rude, using no honorifics at all and using "ore" (a boastful way of saying "I") to refer to himself. When speaking to those his age, he refers to them with "omae," a form of "you" that is sometimes used between friends, but Rinji's usage implies that he is of higher status than who he is speaking to. For those he doesn't like, such as the Legendary Warriors, he uses the word "temae," a rude form of the word "you." Rinji uses one pronoun toward Takuya exclusively: "kisama," a very rude from of "you" directly toward those who anger the speaker. In the English version, Rinji speaks similar to Yoda from Star Wars, sometimes putting verbs at the end of his sentences (Ex. "A chance at beating me, you haven't.") He speaks in the third person at times. In both versions, he gives his fully honest opinion when asked for it, no matter how rude he may end up being. He hates feeling inadequate, and does everything he does to his fullest ability. Rinji's rivalry with Takuya is fueled by jealousy, and Rinji always tries to break Takuya down no matter how he does it, such as kidnapping Kazemon after Takuya and Zoe get together.
Rinji views pacifism as a pathetic concept and always attempts to solve his problems through battle, to the point that even Venusmon's techniques have no effect on him. The only people he is known to be remotely kind to are his own family or those who admit that they are weaker than him.
Rinji is left-handed, and as such, he holds his D-Tector in his left hand and forms the Fractal Code in his right hand when he Spirit Evolves.
Rinji enters the story as a junior high school student in Odaiba. He is a fierce rival of Takuya Kanbara, and the two of them have been trying to outdo each other since the day they met. When he overhears a message to Takuya telling him to return to the Digital World, he sneaks along by hiding in a compartment of their Trailmon. Rinji then learns about all Takuya has done, as well as his status as a Legendary Warrior. Jealous and insulted, Rinji vows to become better than Takuya by one method: he would defeat the Legendary Warriors. Releasing a Lampmon he finds from its prison, Rinji wishes for the ability to defeat the Warriors, yet not outright kill them. Lampmon acquires data from all ten Warriors and combines them into one object: the Spirit of Combined Power, which allows Rinji to become Desetamon. Rinji's phone becomes a D-Tector and stores the spirit. Rinji demands a Beast Spirit as well, but Lampmon states that the Beast Spirit will awaken when Rinji truly needs it. Lampmon is correct, as before he is destroyed in a battle with Megidramon, Rinji's Human Spirit releases a white orb, which forms into the Beast Spirit of Combined Power and changes Rinji into Leadramon. Unlike the original ten, he does not have an Ultimate Human Spirit form, as his spirit is artificial.
Rinji encounters the Digimon goddess Venusmon (before the Megidramon encounter), and the meeting is rocky, to say the least. Venusmon attempts to convince Rinji out of his desire to defeat the Warriors, stating it is pointless, only to have Rinji throw it in her face that she is pathetic in true combat, as her "attacks" cannot cause pain, which is the only true way to win. Rinji Spirit Evolves and attacks Venusmon to prove her as weak. Venusmon attempts her soothing attacks, but to her horror, none of them slow Desetamon down at all. Desetamon tells her that his heart is tuned to fight, and battle is his only goal: His only method of operation is to fight. Venusmon's god-like power level prevents Desetamon from doing much damage, making him realize that he is not omni-powerful and must train harder. Before he leaves, Rinji gives Venusmon a harsh warning: "Stay out of my way, or you'll fall from pain quicker than Devimon fell from grace."