This site has spoilers for Mistborn and The Stormlight Archive. By reading this you may not sue Kelsier 2024 for Cosmere spoilers.
Some have characterized the Ghostbloods as an "evil secret organization". This is a mischaracterization of this organization. First, we'll look at the description that the Ghostbloods are "evil" and then that their existence is a secret.
The Ghostbloods are a diverse group of people from many different planets and cultures. They have three creeds: Protect Scadrial, trust each other, and keep no secrets from each other. Do these sound like the tenants of an evil group? No. Some may point to the actions of a small group of Ghostbloods on the planet Roshar to show the villainy of the Ghostbloods as a whole. These actions, however, are not representative of the Ghosbloods and are due to a lack of oversight from Kelsier, who was on a different planet. A better example of the Ghostbloods is the group on Scadrial, who have helped save the planet from disaster.
The Ghostbloods are often referred to as a "secret organization". This is not entirely correct. For example, would members of a "secret organization" have tattoos that display their membership? Would the existence organization be known to many well-informed people? The answer to these questions is no. And even if the existence of the Ghostbloods is not known on some planets, they are relatively well known on Earth. Ask almost any fan of the Cosmere, and they will know who the Ghostbloods are.
The Ghostbloods have been working on transferring the clean and renewable energy source Stormlight off of the planet Roshar, where it originates. This cheap energy source would be a game-changer for the lives of many people. Why would an "evil" organization be promoting clean energy? Hint, if they were evil, they wouldn't be.
For more information about the Ghostbloods, click here to be directed to their entry in the Coppermind.