Sleepwalking:

Kayden is connected to the Leviathan via a birthmark on her left rib cage, and due to the distance put between them, the Leviathans’ subconscious causes the sickness, but feeling Kayden almost die, the sickness goes away and instead lends itself to her affinity with water and ice. The nature of her sleepwalking is partially tied to her connection to the water, as it gets more frequent the closer to water she is and she always walks in the direction of water (unless she has very strong ties to someone then she sleepwalks to wherever they are or in their direction).

Brittleness:

Due to the nature of her childhood and how she grew up, Kayden may not seem brittle to most at first. This is because her shell is “decorated” as she has learned to react to situations like most people would. She will flinch if she gets hit when she remembers to, she’ll act annoyed when she can tell someone is trying to annoy her, but it is generally an act. Part of her is grateful for the shell she has, since she can oftentimes be genuinely calm during times of panic and trouble, until the panic becomes too much, then her shell starts to crack, and she has a short amount of time before the shell will break and she will become extremely emotionally volatile/emotionally raw. This is also part of the reason why she trained to take hits, because she can take hit, after hit, after hit, after hit, with very little or no reaction, until her breaking point is reached, and suddenly she doesn’t take it with no reaction anymore, but she fights back, the raw essence of her soul, this fury, is unleashed.