I loved this Unikitty Character so much I put him in TMNT!
Sensei Falconeye Dillan was a martial arts action hero trainer and an old friend of Master Splinter back when he was Hamato Yoshi. He knew about Tang Shen and Miwa, as well as Oroku Saki, and while he knew his friend survived Shredder's attack, he belived he had died shortly after when he disappeared due to being mutated, and they lost contact with each other. Falconeye himself had two sons he adopted from infancy and trained in the arts of a martial arts action hero: Hawkeye and Eagleclaw Dillan. He loved both of them, and trained them well. But soon, when he gifted Hawkeye his sunglasses and the right to succeed him as sensei instead of Eagleclaw because he was hotheaded and Hawkeye was more mature, Eagleclaw went down the dark path and destroyed most of their dojo before being stopped by Hawkeye. After Eagleclaw was sent into hiding, Hawkeye left the ruined dojo to protect the world from people like Eagleclaw, and Falconeye stayed behind to rebuild his dojo. Years later, after the death of Master Splinter and the defeat of Shredder, he decided to see his son again, and was shocked to find his son mutated into a Crocodile-Hawk mutant hybrid and working for Karai in the New Foot, and had to catch up on everything that happened, also finding out what happened to Splinter and mourning his fallen friend. Soon after meeting the Turtles, the group was attacked by Eagleator and Sensei Falconeye saw the true extent of his other son's descent down the dark path. After teaming up with the Purple Dragons, Eagleator fought against his brother Hawkodile for his shades, and while Sensei Falconeye was fighting off Purple Dragons, he got doused with mutagen and a few DNA samples, transforming him into a mutant hybrid of a Falcon and a Komodo Dragon. Now calling himself Falcomodo, he aided his new allies and came between his two sons, driving off Eagleator and scolding him for ruining their relationship, to which Eagleator countered that it was his father's fault for not giving him those shades when he clearly deserved them, so it was apparently HIS fault their relationship was ruined. After thanking the Ninja Turtles for helping his son Hawkodile, he decided to open his dojo's doors to Mutants to teach them how to defend themselves and become heroes.
Art by https://www.deviantart.com/ezio1-3 after asking permission to post his artwork