Way up top, a flat expanse, Where light and shadows dance. Not a wall or floor - no how, I'm probably above you right now.

I see you live, I'll see you die. I see you sleep, I see you wake up. As I see your life slip by. That's why they call me a

Guard the night, weapons tight. Defend the place, walk the space. The first three, on the back, a compliment or assurance. Next three sounds like a dodge, a royce or a sushi.

I am the highest point of a wave's short life, A symbol of status in times of strife. I am found on a helmet, a hill, or a bird, A sign of a lineage, though I'm never heard.

What is known to be able to make two people out of one?