system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] Is Sauron a reality warper? When was the height of his power, before or after he forged the Rings? What could he do with the ring that he couldn't on his own? Could every wizard working together mimic/match/exceed his most impressive feats? Is he even 'dead?'
gpt
Is Sauron a reality warper? No, he's more of a master manipulator. Think Mind Stone, not Reality Stone.

The height of his power was after he forged the ring and still had it in his possession. By putting part of his soul into the Ring, he was able to amplify his power tremendously. 

The evil of Sauron and the Ring mainly takes the form of the power to dominate the wills of others. Before the ring he worked mainly through manipulation and intimidation. With the Ring he could bend whole empires to his single-minded goal.

When Maiar like Sauron take on a physical body, it is a long-term decision and  effectively permanent. The body is immortal and more powerful than a human body, but it can be killed and that is still a traumatizing experience. It can take a very long time--as in, centuries--before they regain enough strength to act and speak even in spirit form, and longer before they can take on a new body. That's pretty much all Sauron was doing in the time since he lost the Ring, regaining strength (by the way, there may be some confusion, but by the time *The Lord of the Rings* occurs, Sauron has indeed regained a physical body).

As long as the Ring exists, even if Sauron doesn't possess it, that part of his soul is still alive in the world and in some kind of synergy with himself. When the Ring is destroyed, that part is lost permanently, Sauron dies of shock, and he no longer has enough spirit left to ever take physical form again. It is left ambiguous whether he is dead in the ultimate sense or just so diminished in spirit that he may as well be.