Koya was Shredder's pet falcon whom he used for recon missions. Determined to bolster his ranks, Shredder has Koya mutated into a weapon serving the Foot Clan.
First Battle with the Turtles
Koya's first mission is to find the Turtles in which she does, as they're found hiding outside the city in Northampton recovering form their latest battle with Shredder. Koya is ordered by Karai to stand by for reinforcements.
The next day Koya attacks together with Foot Assassin ninjas and they quickly engage the Turtles in battle. Believing Alopex whom had defected from the Foot has betrayed them. Raphael in a rage attacks Alopex leaving his brothers and Splinter at a disadvantage. Koya takes this moment to attack Splinter whom is still suffering from a broken leg given to him by Shredder. Koya easily gains the upper hand until Leonardo appears to challenge her.
Leonardo fights Koya until the falcon slashes him with her wings. Leonardo then unleashes a shuriken attack wounding her. Koya presses her attack against both Splinter and Leonardo regaining the momentum until she's jumped by Raphael and the two go crashing outside of the barn. Hoping to gain an advantage, Koya plans to use April O' Neil and her mother as hostages until Michelangelo puts a stop to this idea by landing a motorcycle across her head. Defeated finally, Koya asks Leonardo to kill her. The Turtle refuses and instead removes the shurikens from her body and warns Koya that she still has a chance to survive if she leaves. Koya and the ninjas retreat vowing revenge.
Shredder and Krang's Failed Alliance
When the Shredder decides to meet Krang aboard his ship at sea to form an alliance. The meeting turns into chaos as Krang attempts to kill Shredder. The ninja is hopelessly out numbered until his mutant creations Bludgeon and Koya appears. Koya engages Krang's men and quickly the battle goes in Shredder's favor. Shredder heavily damages Krang's robotic body and is preparing for the finishing blow, but due to damage to the ship caused by Bludgeon, Koya feels forced to flee with Shredder and save her master from possibly drowning.
Once the ship begins to quickly sink, Bludgeon retreats after Koya snags Shredder, with their leader telling them both that the Foot Clan is at war. Koya is next seen together with Shredder and the assembled Foot Clan as they're greeted by the robotic turtle Metalhead.
Koya is extremely loyal to Shredder and the Foot Clan, and will follow orders without question. She is perfectly capable of handling herself as she fought Leonardo and Raphael on separate occasions either gaining the upper hand or to a stand still. She is very quick, and can use her wings as slicing weapons. Koya has also boasted that she can see for miles; the falcon is quite cunning, and willing to do anything it takes to win.