Mist and Carbon and Opal. What do I think about them?
They are certainly an interesting bunch. Yes, it's weird that she was able to pull her copy out from the void and she must have a strong connection to Eitris to have that sort of power and to be given a dragon. Why did she have a void-self in the first place? Is that something everyone has? What happened in the void now that Carbon is gone? These are interesting questions but I honestly lack the energy to put too much thought into answering them. I have to focus on our quest and on my friends. They have to come first. Always.
I'm unsure if it is wise, that they'll join us. Floofy pointed out that having a dragon on our side is probably good but Opal seems rather peaceful and none of them look like they have ever been in any sort of fight. Grerv is right, we cannot trust them. They might have good intentions but I doubt that they are capable of handling this. They don't know what they are getting into.
But in the end, that is not for me to decide. I guess, if it is Eitris' wish and Mist's destiny to fight this cult, there is little I can do to stop them.