>Look at our left hand
>Oh, you have a tattoo now! It looks kind of like a badly drawn and asymmetric radiation symbol, if the top two triangles were more rounded, and the bottom one didn't exist.
>You are aware that this is a Command Seal, the things you've read on the Grail Wars makes clear their purpose and meaning. They are the mark of your right to be in the Grail War, and proof that you are a Master. Should you lose it, you are out of the running and cannot win unless you can somehow recover it. More importantly, they allow you give absolute commands to your servant, commands that cannot be disobeyed no matter what. These commands may break the laws of magic and reason to an astounding degree; calling your servant from miles away in an instant for instance. On the other hand, you may use them to force them to violate their own codes of honor or engage in acts they would never agree to normally. If you understand properly, each mark represents one charge of the seal's power. Used three times, the seal vanishes and you are done. So, in reality, you have two uses, and one for an emergency if you value your life more than the infinitesimal chance of victory in a hopeless situation.
>Now that you are looking at it, it is no longer itching.
>_