In 1940, when he was 36, Kent gained possession of the Helmet of Fate and became Doctor Fate. During the years that followed, he joined the Justice Society of America. He also met and married a woman named Inza, who Kent would often call a "Spitfire" due to the fact she challenged him constantly and refused to ever let him get away with anything.
In 1945, Inza convinced Kent that there was more to life than being a hero and he stopped putting on the helmet.He continued his life as a superhero though, fashioning himself a new helmet that covered only half his face, but had no connection to Nabu. He used his own mystical knowledge and the powers absorbed when he wore the helmet, but they were nowhere near his old level. He continued to protect the actual Helmet of Fate, keeping it hidden in the Tower of Fate in Salem. Inza eventually died in 1998, and Kent spent the rest of his life alone, heartbroken by the loss.
Kent traveled to New Orleans and requested that a local psychic named Madame Xanadu perform a seance so that he could speak to Inza again. However, Kent summarily proved Madame Xanadu to be a fraud, to his own disappointment. Before he could leave, Kent was captured by Abra Kadabra, although his cane was not taken.
For twenty-three days, he was tortured and questioned by Abra Kadabra and Klarion, who wanted to know where Kent had hidden the Helmet of Fate, but Kent refused to tell them. On August 19, Red Tornado sent the members of the Team (minus Robin) to see if Kent was okay, and gave them a key to the Tower of Fate. By accessing the tower, they also inadvertently provided Abra Kadabra and Klarion with a way inside.
Abra and Klarion continued to try to make Kent lead them to the Helmet, but he was rescued by Wally West and Artemis. He led Wally to the Helmet, but Klarion followed, and Klarion mortally wounded Kent, who only managed to cast one final spell—a bubble to protect Wally while he convinced him to don the Helmet of Fate. In doing so, Wally's body was taken over by Doctor Fate, and both Wally and Kent's souls were drawn into the Helmet. Inside the Helmet, Fate explained to Wally the workings of the Helmet, and happily awaited for the battle to end so that he would be reunited with his wife in the afterlife.
However, after Doctor Fate defeated Klarion, Nabu declared that he would keep Wally's body permanently. Kent convinced Nabu that Wally was not a suitable host, and offered to stay with Nabu until a replacement could be found, foregoing his chance to ascend and be reunited with Inza.
When Zatanna used the Helmet to fight against Klarion, Kent objected strenuously to Nabu retaining control of her body. Nabu released Kent into the afterlife, because he did not want to lose another host body.
Technically, Kent Nelson is a normal human being with apparently no superhuman or magical abilities. However, since gaining the Helmet of Fate, Kent's body gained impressive magical powers as Doctor Fate. Without the helmet he is not as powerful, but can still perform assorted magical feats.