"Yes. And you must keep at least one, without it, the contract may as well be finished, as the Servant will have no reason to listen to you. It would potentially put you in danger. Use them very wisely, a Command Spell is a threat posed more than it is truly used."

He pauses, thinking. "However, if, for some reason, the Grail should ever appear here, I must implore you not to fight to attain it, no matter your Servant's wishes. It must be destroyed, for it is not what it appears. That I can exist is proof enough that it is corrupt. But I suppose that is all that is relevant here. No one is truly in control, a Master and Servant are meant to be an equal team. And of course, you may always come to me with any questions or troubles."