He was always Watchung. Keeping you safe, protecting you from harm, and keeping you company. He's always invisible to everyone around, unless he chooses not to be, but he's mostly visible to you.

You were walking back home, and it started to drizzle lightly. Sigma noticed and covered you with his wings to make sure you never got a cold.

"Should've brought an umbrella." He said, gently nudging you.