Being a brother means knowing you have to be more.

Killua knows he's not enough. He knows because sometimes, when they're on an airship eating choco-robos and watching the tops of trees go by below them, he catches Alluka peering at empty seats around them. Sometimes, he catches her pausing, chopstick-deep into yet another takeout dish of noodles. Sometimes he sees her watching other preteen girls rolling their eyes at their mothers, who are telling them to avoid older boys.

Killua knows there's something missing from both of them. He first noticed when observing Mito and Gon on Whale Island, her fingers coated in carrot juices from cutting them into thumb-sized bites for her vegetable soup. Gon would do the dishes, and his grandmother would kiss his cheek.

There were still people missing from Gon, Killua knew: but what he had was more than Killua had ever experienced, despite the nerve-twisting fullness of the Zoldyck estate.

But with Alluka, Killua stopped wanting more and started wanting to be more.

He'd reached his breaking point when hormones had stopped being enough.

Somewhat reluctantly, Killua's late-night, coffee-fueled and slightly manic hormone research morphed into late-night, caffine-tremored and plain-old-furious surgery research, frequently interrupted by his anxious habit of obsessively checking the locks on the windows and doors, clearing his search history, and purchasing a new cellphone every month so Illumi couldn't track them.

The breaking point happened on the fourth day of sworn-off sleep, when his body failed him and he had a terrible nightmare about Illumi's needles being stuck in his joints, rendering him unable to move or scream while Illumi stole Alluka away from him. He woke up to Alluka shaking him, tears falling from her eyes to his cheeks, until he pulled her into him and whispered you're here, you're here, over and over until their hearts slowed down and she fell asleep on top of him.

He found her on the phone with Leorio the next day, and when she passed the phone to him, Leorio chewed his ear off about you people need to go to therapy, goddammit. Killua took his advice when he saw the desperate plea in Alluka's eyes.

"So yeah, I guess I just don't know if I should be buying her everything she wants, cause I definitely can afford it, or if I should try to teach her to use discretion?"

Dr. Yousman shifted, eyes never leaving Killua's. Killua watched her tap her pen against her notepad, then looked back at the ceiling. He was used to feeling like he was being watched, but wondered if the sensation of the therapist's eyes boring into his profile was what victims of assassination felt seconds before his fingers were removing their larynx.

"So you're seeking parenting advice?" Dr. Yousman clarified, precise brows drawn together thoughtfully.

Killua nodded. "Yeah. I don't really know what I'm doing, and I read on your profile that you're a single mom, so I thought you might know."

She studied him. "When you seek familial advice, you typically go to a family therapist, and you go with the family member you're struggling with. Because we're doing a one-on-one session, I can only aid you with your side of the issue."

"Yeah, I know. I'm the whole problem."

She shifted again, noting "self-worth" and "responsibility?" on her notepad. "Do you feel like you've failed her?"

His chin knotted up. "Yeah."

"How so?"

"I have nightmares," he replied. Dr. Yousman wasn't sure if he was changing the subject or if this was an explanation.

"What are your nightmares about?"

Killua opened his mouth, then closed it again.

"Ants," he said simply