Isildur used a broken sword to cut the Ruling Ring off Sauron's hand. Sauron was fatally wounded by Gil-galad and Elendil as Sauron killed them. Gandalf took the job of blocking the Balrog - and he was barely able to defeat the Balrog (in fact, he died in the process). A few reasons.
In the books, Isildur did not defeat Sauron; it was his father Elendil and the Elf King Gil-galad who defeated Sauron together at the cost of their lives. Isildur cut the Ring from Sauron's dying body, and his spirit fled.
Isildur took up the hilt of the sword and used the broken blade to cut the One Ring from Sauron's hand. Sauron's spirit fled from his body, but as long as the Ring that held much of his power survived so would his spirit.
Why didn t Isildur destroy the Ring when he could?
Pushing Isildur Into Mount Doom Would Lead to War
In another passage from The Silmarillion, Elrond and Círdan counseled Isildur to destroy the Ring, but he refused, saying, "This I will have as weregild for my father's death, and my brother's.
Isildur features briefly in voiced-over flashback sequences of Peter Jackson's The Lord of the Rings film trilogy. The video game Middle-earth: Shadow of War departs from Tolkien's narrative by having Sauron make Isildur into a Nazgûl or ringwraith.
How Sauron was overthrown: Gil-Galad and Elendil's last battle - LOTR LORE
Is Celebrimbor a Ringwraith?
As his "lifeforce" is imbude in the ring which prevents him from going into the Elven afterlife, and as such keeps him in the mortal plane. But he is a wraith in the first game, before his new ring is ever created. The ritual done to Tallion at the beginning of Shadow of Mordor summoned Celebrimbor into Tallion's body.
As one of the Ringwraiths, Isildur was forced to serve the Dark Lord for all time, until he was defeated and freed by "Talion". Later, the Ranger claimed his ring to survive after Celebrimbor abandoned him, and eventually took Isildur's place among the Nazgûl after holding back Sauron's forces for decades.
The One Ring was an ancient artifact created by the Dark Lord Sauron in the Second Age for the purpose of ruling over the Free peoples of Middle-earth, mainly the Elves. It was also known as the Ruling Ring, Great Ring of Power and Isildur's Bane (due to it causing the death of Isildur).
In the spiritual world, beings are invisible to those in the physical world. This is why Isildur, Bilbo, and Frodo become invisible when they wear the Ring—because they are no longer in the physical world. As Olsen said, Sauron does not have a real body, so he is not affected in the same way.
There had been no communication from Moria for quite some time, but no one knew exactly what had happened there, or why the colony had gone silent. Gandalf definitely did not know about the Balrog, or even about the orc attacks that had sent Balin and all who were with him to an early grave.
Isildur claimed the Ring from Sauron in II 3441 (the final year of the Second Age), at the end of the Seige of Barad-dur. He lost it at the Disaster of Gladden Fields in III 2. Thus he was Ring-bearer for somewhere between two and three years.
The Elven King named Gil-galad fought side-by-side with Elendil, the King of Men. Together they managed to mortally wound Sauron, but the fight cost them their lives. This is when Isildur, son of Elendil, took his father's sword and cut the Ring from Sauron's hand, dealing the final blow.
Isildur lives a total of 234 years before he's killed by Orcs early in the Third Age, but it's already clear The Rings of Power isn't sticking to this exact timeline.
Morgoth, the first to reign terror upon Middle-earth, was more powerful than Sauron and commanded an army of dragons and Balrogs. While both Morgoth and Sauron were cunning, Morgoth's rule and terror lasted longer and his corruption spread further, making him more formidable in the Lord of the Rings universe.
"So I think in his pitch to Galadriel, it cannot mean that he loves her or that there's any kind of romantic relationship. There should be no ambiguity around the fact that Sauron is evil — he's terrible, and he's using Galadriel to enhance his power."
What happened to Sauron when Isildur cut off the Ring?
As a result, while cutting off the Ring did destroy Sauron's body, it didn't destroy his spirit, and thus paved the way for Sauron's eventual return, even without a proper physical presence. This is why his will is carried out by those who serve him in The Lord of the Rings, like the Ring-Wraiths and Saruman.
In order to make such a weapon, the crafter themself would need to be just as corrupt and be able to provide some of their life force to keep it powered. So unless an equally evil being held the same ring-making knowledge as Sauron, it was impossible to make another.
The Dead are following." The Dead Men of Dunharrow or Men of the Mountains, referred to in adaptations as the Army of the Dead, were Men of the White Mountains cursed to remain in Middle-earth by Isildur, after they abandoned their oath to aid him in the War of the Last Alliance.
After the war ended Elendil was dead. Therefore Isildur, his eldest son, was then the (last) rightful king of both Gondor and Arnor, and therefore his descendant Aragorn was also the rightful king of both kingdoms.
The sons of Eärendur quarreled, and while Amlaith was the Heir of Isildur and his father, the other sons broke the kingdom into three separate realms. Of these, Amlaith ruled Arthedain, the only that was ruled by the Heir of Isildur. The other kingdoms were slowly overcome by dark forces of the evil land of Angmar.
Because of this letter, it is quite clear that not only did Sauron carry the Ring while he was in Númenor, it was actually the Ring's power that allowed him to so quickly corrupt the kingdom.
Defeated by the Host of Valinor in the War of Wrath, Morgoth was banished from Middle-earth into the Timeless Void, though it was prophesied that he would one day return.
Isildur perhaps feels a longing to explore this aspect of his heritage - just like his brother - by venturing to his ancestral home (we already know Elendil hails from the west because Queen Regent Míriel admitted so in The Rings of Power episode 3).
How many years were there between Isildur and Aragorn?
Not long after, Isildur and his brothers were ambushed by Orcs on the road, and during a desperate attempt to secure the One Ring he was shot with an arrow and left for dead. This was only two years into the third age of Middle-earth, and around 2,929 years before the birth of Aragorn in 2931.
