Closing his eyes to grasp better concentration, Jonathan did everything he could to unseal his powers.
With the keys time power, Jonathan knew he had every chance to unseal his mistake and break right into the God rank which he couldn't in the past.
However, nothing serves as a free meal, and not only he knew this but Greg too.
Because the key was something that the Creator made, its power was far more scarier than anything else. It is not a coincidence that only that can obtain the keys who had the Blessing.
Because Greg has already obtained 3 keys so far, he clearly knew what they could do. The fire key could wound Wayne and Russ even though they were far above the Evolution Step, while the stone key could turn anything into solid stone.
But it seemed that those two key's power was kid's play compared to this one.