I am two-faced, but bear one head. Men spill their blood for me. I have no legs but travel widely. I make kings immortal. I am potent when shared, Yet lust for my power keeps me locked away.
Money (coins specifically). Coins have two faces, heads and tails. People fight for money, and money travels far and wide. Kings live on when they’re depticted on a coin. Sharing money with others is a meaningful experience yet many people keep their money locked up.
Breath. Air is light, but even Stig Severinsen, the world record holder can only hold his breath for 22 minutes. The world’s strongest man can’t beat that, but you can have the pleasure of telling him to his face.
The Pope has it but he does not use it. Your father has it but your mother uses it. Nuns do not need it. Arnold Schwarzenneger has a big one, Michael J. Fox’s is quite small. What is it?