[ Katherine - Kat - Aqua ]
Aqua bears some similarities to Kairi and Sora, primarily in her sisterly affection for her closest friends. This is displayed by when she makes lucky charms for them, does everything in her power to protect Ventus (despite his apparent discouragement whenever she tells him to go home), her confidence that Terra will overcome the darkness, and when she strands herself in the Realm of Darkness in order to save him. Aqua is also shown to be very sociable with children, quickly befriending Kairi, Sora and Riku. Aqua is remarkably calm and dead-set on her goals, and only threats on her loved ones seem to make her lose her composure. Although, like Sora, Aqua is comedically insecure in a romantic sense, so when Zack asks her out on a date, she shakes her head, wildly waves her arms, avoids eye contact, stutters, and blushes, desperately trying to compose herself. She also quickly changes the subject when Hercules asks why her face is red.
Aqua is typically modest, referring to herself as a trainee (only calling herself "Master Aqua" before she fights Terra-Xehanort, even then only as an intimidation tactic) and acting very respectful toward elders and authorities such as Master Eraqus, Queen Minnie and the Grand Councilwoman. However, like Eraqus, Aqua is also strict, stubborn and overprotective, which sometimes makes her seem condescending. She always worries about Ventus because of his age and lack of experience, ordering him to go home whenever she finds him without giving him a chance to prove himself.
However, despite her flaws, when the situation demands it, Aqua's overall skill, determination, intelligence and kindness make her the most reliable and competent out of Eraqus's apprentices, and unquestionably worthy to be a Keyblade Master.