Kaina is a serious and disciplined woman who does not hesitate to hurt people to fulfill her mission or achieve her goals. She can be very casual and relatively fearless, showing no visible fear upon meeting All For One and even familiarly addressing him. Kaina is direct and ruthless toward her adversaries, firing a warning shot at Izuku Midoriya and threatening to dismember the young hero should he not come quietly.
In the past, Kaina had an optimistic outlook in her desire to be a great hero but was led down a dark path by her superiors, having been trained to kill villains and corrupt heroes, sometimes unjustly, who were threatening to disrupt the order in society. Her repeated killings made Kaina disillusioned, and she soon fell into a depressive state upon realizing that the Hero Commission maintains a fragile and hollow peace at the expense of others while hypocritically justifying that their actions are for the good of everyone. Upon seeing some young children in admiration over her, Kaina eventually reached her breaking point, realizing that the youth of society wholly admire Heroes and wish to become them while not being aware of the bloodshed behind the scenes. While reaching out to shake the hands of said children, she saw how bloodied her hand was and retracted it in horror, not wanting to pass said bloodshed on to them. Upon implying that she wished to leave her post and receive a veiled threat to her life in response, Kaina finally snapped and killed her superior.
As All For One had declared, Kaina wishes to see the downfall of Hero Society, knowing just how corrupt it is underneath, and stated that the Symbol of Evil's rule would be preferable over the corrupt system she spent years serving under. She also shows pity to the victims of the heroic society, such as Kai Chisaki, yet is also willing to put his life in danger to distract and gain an advantage over Izuku.
Izuku, however, pointed out that Kaina wasn't serious about killing Kai because the trajectory of the bullet she fired at him was off, and he surmised she wasn't as supportive of All For One as she claimed to be because she could've easily fulfilled the contract to capture Izuku without engaging in battle. It is later proven that despite her low hopes and cynical view of society, she still cares about doing what's truly right in the end and that she became a hero with the good intention of helping others. After witnessing Izuku's skill and resolve in battle, as well as how he managed to save both Kai and her with no hesitation, Kaina deems Izuku to be a true hero. Kaina even went as far as to give him a clue about All For One's potential whereabouts (though she didn't know it was a trap) and willingly put herself at risk, given the severe injuries All For One inflicted upon her, to aid Izuku against Tomura Shigaraki in the Final War.
