What Am I Riddles

Question: I sit on a bridge so you might see just how clear the world can be. What am I?

Question: I was crucified to keep murders out of the maze. What am I?

Question: sometimes i hang, sometimes im crusty, sometimes im bloody, and yellow. What am i?

Question: What lightens the light and darkens the dark?

Question: I always listen to my Master, I never disobey. From my path I never stray to destroy what's in my way. What am I?