Loki

"I, Loki, Prince of Asgard, Odinson, the rightful King of Jotunheim, God of Mischief, do hereby pledge to you, my undying fidelity."

- Loki to Thanos

Loki Laufeyson was born to the ruler of the Frost Giants, Laufey on Jotunheim. He was found by Odin after being abandoned shortly after his birth, and was taken to Asgard, where he was raised alongside Thor and Aurora as Asgardian Royalty by him and Frigga.

A Royal Object (Fanfic)
We first meet Loki when he is only 8 years old. He and his sister, Aurora are playing a prank on Thor, during which Loki turns into a snake and tricks his brother, before transforming back into his usual form and stabbing the boy. Meanwhile, Aurora is hiding in the bushes, and comes out when Thor is stabbed to drop a ball of water on his head.

When the Rainbow Bridge starts shaking and Aurora starts to fall off, Loki is the one to hold onto her whilst Thor goes to get help from Heimdall. Loki starts crying and begging his sister to hold on, and after she falls off the bridge and into the Transportation Beam, he is the person to be the most emotional and impacted by her death.