Easily, really. Careful manipulation, and then, once the Grail was at hand, to eliminate the Master and use the prana generated by his book to stand on his own long enough to achieve his goal. But then, he hadn't needed the Grail any more once Jeanne had returned. He had been so very lucky.

"It was lucky for you that you were not." There was a playfully dark note to his voice. "But it was much pleasanter for me to find my Master to be such a pleasant fellow."