Key differences between Hela's character in the MCU and comics
Thor: Ragnarok revived the mediocre Thor franchise in the Marvel Cinematic Universe with humor and well-written characters. Another major reason behind the success of the 2017 film was undeniably Hela. As MCU's first main female antagonist, Cate Blanchett's Hela did a great job of being a badass villain. While her comics counterpart is also extremely powerful, there are many differences between the two versions.
Hela is Loki's daughter in the comics, not his sister
Hela was shown as Odin's firstborn in the movie. But, in the comics, she is the daughter of Loki and giant sorceress Angrboda, which makes her Odin's granddaughter. This is the reason why her comic-accurate costume looked similar to Loki's attire. Her parentage in the film was slightly based on Angela, Odin's estranged firstborn, who was the Queen of Hel for a brief period.
Her magical abilities go much beyond just infinite weapon creation
Hela's primary offense mode in the film was her necroswords. While this is similar to her usage of Night Sword in comics, there she mostly relies on her magical abilities. In comics, she can kill with a mere touch, grant immortality, raise the dead, teleport, create illusions, release magical blasts, and whatnot. On-screen, her magical abilities were limited to infinite weapon creation.
Hela's cloak gives her all of her powers
In MCU, Hela was so powerful that Thor had to cause Ragnarok to defeat her. But in comics, it is all about her cloak. The left side of Hela's body is decayed because she was born half-dead. She conceals this by wearing a magical cloak, which not only makes her look beautiful, but also grants her all the powerful magical abilities.
She actually helped in bringing Ragnarok on Asgard
Continuing the topic of Ragnarok, Hela's role in the destruction of Asgard is instrumental in both media. While it was caused to defeat her in the movie, in comics, she helped her father Loki in bringing the cyclical apocalypse on Asgard. Here, she oversaw the construction of Naglfar, a ship built from the fingernails of the dead, which caused destruction in the Nine Worlds.
She was actually appointed as the ruler of Hel
Instead of being banished to Hel for her blood-thirsty tendencies, in comics, Odin appointed Hela to rule Hel and Niffleheim. Here, she became the literal Goddess of Death due to her duty of ushering souls into Hel. In MCU, the title of Goddess of Death referred to her murderous achievements and had no connection to dead souls until she raised the army of undead.