There are other theosophical works but I won't bother citing them, you can easily access them by going to places like theosociety, agni yoga society, etc etc.
The one I think is more important than HPB almost is "Leaves from Morya's Garden" though of course, that's just one. It has a strangely transhumanist outlook.
As for you, I'm correct. Icke literally says he met one of the "ascended masters" but it's name is slightly different. I don't care to dig up his book title. The United Nations is literally shilling muh vibration all the time, you think they don't have plans to co-opt that too? There WILL be more terror, and you will not escape. No one will.
To see where I'm coming from, try to contrast some of HPB's work, or Roerich, with pic related. Whatever is about to happen has already been planned by the UR-Lodges. Something worse than expected is coming, and it's far too obscure to summarize.