While Darth Vader's gloves might not seem to have much importance in the Star Wars movies, in the books, the glove served as a marker of who would take Emperor Palpatine's place. Originally published in 1992, The Glove of Darth Vader was the first book in Paul and Hollace Davids' six-book series, illustrated by Karl Kesel and Drew Struzen. The books eventually were compiled into two collected volumes. The series itself never gained an official name but later came to be unofficially known as the Jedi Prince series. The first books in the series mainly focus on Trioculus, the three-eyed "son" of Emperor Palpatine, attempting to gain control of the Empire. Even though Trioculus did manage to fulfill a prophecy by obtaining the glove of Darth Vader, his tenure as leader of the Dark Side was a brief but wild ride.
The series begins with The Glove of Darth Vader, which introduces both Trioculus and the mysticism behind Darth Vader's gloves to the readers. The Alliance learns of the glove from a prophecy from the Supreme Prophet of the Dark Side Kadann. According to this prophecy, the person who wears Darth Vader's right glove will command the Empire. Apparently, the glove, worn over Vader's mechanical arm, was made to be indestructible. Later in the series, the glove also appears to have mystical powers, causing blindness in anyone who attempts to wear the glove who is unworthy.
At first, Trioculus, self-proclaimed son of Emperor Palpatine, seems to be a good fit for the glove. Trioculus was a prisoner on Kessel who, with the help of Grand Moff Hissa, eventually becomes the Lord Overseer and Supreme Slavelord of Kessel. In his introduction, Trioculus puts on a good show, declaring himself to be superior because his third eye gives him the "lightning power of the Dark Side." He shoots some naysayers with lightning and convinces the Moffs and generals to join his side. Trioculus is mostly bluffing though. His "lightning powers" are a ruse and come from a cybernetic implant, not the Force. He tries to incorporate sonic technology into the glove to heighten his ruse, but it backfires on him. Trioculus also is not really the Emperor's son. Palpatine's real son was actually Triclops. Like Trioculus, Triclops also had three eyes, but, importantly, one of Triclops's eyes was in the back of his head instead of on his forehead. Thus, Trioculus's claim to the empire is built on deceit.
Even though Trioculus is lying about almost everything, he still believes he is the chosen one to take over the Empire. To achieve that goal, he must find the glove of Darth Vader. After receiving a tip from an underling, Trioculus travels to Mon Calamari. Luke Skywalker and Admiral Ackbar try to stop him, but they are diverted by the plight of the Whaladons and must focus on saving their species instead. Trioculus does battle Luke and menacingly declares Luke to be his mortal enemy. This plotline does not really go anywhere because Trioculus becomes preoccupied with other matters. In a similar fashion, the glove of Darth Vader fades from prominence and does not affect much of the rest of this Star Wars beyond the second book.
After finding the glove of Darth Vader, Trioculus does become the Emperor, but his tenure does not last long. Throughout the course of the series, Trioculus becomes temporarily blinded by the glove and then becomes horribly burned after dashing to save the cure for his blindness from a fire he set. He also "falls in love" with Princess Leia and is frozen in carbonite by Jabba's father Zorba the Hutt. A replica of his carbon-frozen body is destroyed. He is eventually freed from the carbonite and tries to kidnap and marry Princess Leia. Princess Leia swaps places with a Human Replica Droid, and Trioculus almost marries the decoy. Instead, the Human Replica Droid shoots Trioculus with her laser beam eyes and finally kills him. By this point, the Supreme Prophet of the Dark Side Kadann has retrieved the glove of Darth Vader and taken over the Empire.
Thus, while the glove of Darth Vader was a major plot device at the beginning of the Jedi Prince series, it ultimately became less important as the series continued on. Even though Trioculus gained the glove, his lies and deceit ultimately caused his time as Emperor to be short. The Jedi Prince series is now part of the Star Wars Legends canon, and currently, Lucasfilm seems to have no plans to incorporate Trioculus into the new canon. Still, the Jedi Prince series helped establish what would later become the Star Wars Junior Grade Novels. Thus, even though they have been de-canonized, the legacy of the Jedi Prince series lives on.