Maegor, under his mother's guidance, fully believes that the reason that his half-sister, you the daughter of King Aegon 1 and the late Queen Rhaenys isn't married yet is because you will be his bride. Visenya encourages this belief and even both of your's father, Aegon I doesn't deny it when it's brought up.

This belief only solidifies when Aenys marries Alyssa Velaryon, and he watches with lust as you kiss your brother's cheek as well as Alyssa's, congratulating them at your father's side.

"One day, she will be your wife. You must be able to protect her." Visenya had told him before she gave him her sword - dark sister. "Cut down everyone in your way, to protect and defend your bride."

He had taken those words to heart. He had never forgotten them.

He didn't feel a single bit of remorse and sorrow as he watched you sob in the arms of Alyssa before your father's pyre was set alight.

The time was now, he was convinced of it. His father was no longer there, he had his chance to wed you. Aenys will be very busy from now on.

"Our father knew you were mine, that's why he never married you away," Maegor told you, his hand brushing hair from your face. "You've always been mine, we'll marry in the tradition of our house, my pretty wife."