system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] Why did Sauron put so much of his power into the One Ring?
gpt
It was necessary for creating such a powerful artifact. In Middle-earth, creation always requires something from the creator - some of the energy of the soul/spirit must pass into the object being created. Most of the time, the expenditure of power isn't noticeable. Only creating something especially powerful (or "magical", as humans or hobbits might say) costs enough power for its loss to be noticeable to the creator.

Creating a Ring of Power able to master all the other Rings, and with the ability to dominate the minds and wills of others, required almost all of the spiritual power Sauron had left. A lesser being would never have been able to make something like that at all. Even for Sauron, it was significant enough that if the Ring were destroyed, or mastered by someone else, the loss of power would reduce Sauron to a powerless and bodiless spirit.