Newton's third law of motion – To every action there is an equal and opposite reaction.

Chapter 1: Push

Hardship and sacrifice riddled Yukio's life, as demons robbed him of his sense of security at a young age. Instead of yielding to his fear, he endured and trained to become stronger. Thus, although the world remained unsafe, he could protect himself.

By the time he turned fifteen years old, Yukio witnessed the consequence of weakness. Horrific missions where his comrades were injured or killed served as vivid reminders of the cost of just one mistake. Death became so commonplace that Yukio stopped counting the number of funerals he has attended.

During Yukio's childhood, crying helped him deal with difficult situations. However, as the years passed, he realized that tears did nothing to change harsh reality. He told himself that his constant bawling only wasted energy, and he eventually convinced himself that turning off his emotions would be easier. This mindset replaced tears as Yukio's coping mechanism, causing his crybaby tendencies to disappear and allowing development of a calm, polished exterior. Whenever emotionally strenuous circumstances arose, he donned a cold mask to hide his feelings.

Therefore, concerning Rin's demonic nature, Yukio could only act in the manner in which he conditioned himself. He used his sensibility to evaluate the situation surrounding his twin and found himself focusing on two likely outcomes – Rin succumbing to his demonic temperament or the True Cross Order executing Rin. So, Yukio realized the high probability of his brother falling to either Gehenna or the Order.

Although a chance of saving Rin remained, Yukio couldn't keep the possibility of losing Rin from dominating his thoughts. Yukio loved his brother so much that the concept of losing Rin was unbearable. As a defense mechanism, Yukio distanced himself from his twin.

'This emotional void between us is the only way to help me deal with Rin's absence, if that's what the future holds,' Yukio found himself repeating over and over in his mind.

Yukio blamed himself for the tenuous nature of his and Rin's relationship and for their constant sniping at one another. Although Yukio felt guilty treating his brother so coldly, he truly feared what the anguish of losing Rin would do to his mental health. So, Yukio kept his icy disposition in place and continued to push Rin away. Yukio saw this route the only way to protect himself from the possibility of future emotional pain.

Author's notes: I'm using the holiday to try to force myself to get something written, as the words are not coming easily. I've wanted to do something to explore that strained relationship between Yukio and Rin since summer but haven't gotten around to it until now.

I hope you all enjoyed. Next up is "Pull" in Rin's POV, which is making me all sorts of nervous as I've only ever written in Yukio's POV for AoEx…