What exactly happened to Don Elkins?

[Kaaron]

Side question: Did anyone get the feeling that the fifth density "friend" was somehow connected to Don?

Well, Carla mentions in book 5 I believe that Don had spoken to Jim about potentially making some sort of "pact" with the negative entity - and something like that I'm sure reverberates backwards and forwards in time. But who knows.

I feel like because Ra, Jim and Carla were so positive, there needed to be a balance and Don seemed to provide that.
Towards the end of the material, I felt that it was quite noticeable. It was like Don was fixated on controlling events. Trying to save Gandolf, seemed to be him not being able to see the larger picture of progression through the densities. The tarot thing also seemed like an attempt to control the creation rather than be one with it.
I felt a deep gratitude for Don after I realized all of this.
Don went through a horrific ordeal so that we can have a better chance at being harvestable. Not to take anything away from Carla and Jim as I am equally thankful to them too.