This was the manifestation of his plan for years now, no one should be happier than him right now. He was finally getting what he deserved and worked for, what he had always seeked after, his patience and hardwork was finally paying off. No one has had the kind of perseverance he had embodied through out all this time, just to achieve his ultimate goal of turning Egypt into his personal dynasty and ruling it with his consort only by his side.
However, Shai was still very worried and uncomfortable with how things was turning out. It looked to him as if his perfect plan was about crumble on one edge. First of all, he was at least appreciative of the fact that only one the one who cuffs an immortal with the Rosetta stone could take it off and set the immortal free. So it was an assurance to him that Isis could not set herself free nor could any other mortal or immortal. Him and him alone could do that and made him really happy because he still had hold of his consort.