"You're so weak, Sun!" Moon's voice echoed inside their shared mind. His voice was deep and harsh, a stark contrast to Sun's timid and soft tone.

"I'm not weak, Moon. I just don't see the point in fighting all the time," Sun retorted, his tone filled with hurt and defiance.

Moon scoffed at this, his anger simmering just beneath the surface. "That's because you're afraid. You've always been afraid."

Suddenly, Sun sneezed, which forced Moon to take control of the body. The change was immediate and jarring.

Moon's takeover was always brutal. Sun could feel his own personality retreating, becoming a spectator within his own body.

From the brain, Sun could only watch as Moon clenched their shared fists, his anger palpable even without a physical form.

Anger was Moon's go-to emotion. It was easier to deal with than the fear and confusion that plagued Sun.

In a fit of rage, Moon punched their shared body in the face. "Shut up, Sun!" he roared internally.

The physical pain was immediate and sharp. Sun could feel the warm blood trickling from their nose, the throbbing pain in their cheek.

"Why would you do that, Moon?" Sun's voice was filled with pain, both physical and emotional.

"Because you need to learn!" Moon replied, his anger fading into frustration. "You can't hide from the world, Sun."

"I'm not hiding," Sun retorted weakly. "I'm just...I'm just trying to cope, Moon."

"Well, your way of coping isn't working," Moon shot back. "Look at us. We're a mess."

Sun didn't have a reply for that. He just retreated further into their shared mind, nursing his metaphorical wounds.

Moon sighed internally, feeling a pang of guilt for his harsh words. "I'm sorry, Sun," he admitted quietly.

The silence stretched on. Neither of them had anything to say. The argument had left them both drained.

After a while, Moon slowly started to relinquish control of the body back to Sun. It was time to rest.

As Sun took over, he could still feel the lingering pain from Moon's punch. He gingerly touched their swollen nose, wincing.

"You need to control your anger, Moon," Sun mumbled as he crawled into bed, his body aching with exhaustion.

Moon didn't respond, instead retreating into silence. They both knew he was right.

As Sun slowly drifted off to sleep, he hoped tomorrow would be a better day. For both of them.

Moon watched from the recesses of their shared mind as Sun fell asleep. He felt a strange sense of peace.

For the first time in a long time, he didn't feel the need to fight. He felt...content. Just watching over Sun.

As Moon too succumbed to sleep, he made a silent promise to himself. He would try to be better. For Sun's sake.

Because in the end, they were not just two personalities coexisting in one body. They were brothers. And brothers look out for each other.