It recently occurred to me to describe Satanism as "occult-flavored BS." Its "teachings" are NOT occultism, but LIES with the APPEARANCE of occultism. This is why there appears to be a connection between Satanism and various Mystery teachings - Satanism uses occult terminology, symbols, and perhaps even actual bits of occultism, woven together in such a way as to manipulate suckers into believing that they're pursuing black-path occultism (a.k.a. black magic, which is a PERVERSION of occultism, and which is even more evil that Satanism), so that they will perpetrate SRA and become literal Satanic puppets (in cases where this is necessary - there are various motivations behind SRA). Aleister Crowley's writings are the runaway favorite flavor of such BS, for various reasons. Satanists (who don't even know they're Satanists in the vast majority of cases) are prevented from studying actual occultism.
I believe this explains the motive behind using H. P. Blavatsky as a channel for the occult-flavored BS published under her name, which according to Rudolf Steiner, she channeled not from higher spirits, but from humans who were incarnated at the time, specifically in British-controlled India (note that Blavatsky lived in London in this same time-frame). It was intended to become the basis for the occult-flavored BS of the emerging Satanist movement, or of some front for Satanism such as the New Age movement. Some other top Theosophists also spewed occult-flavored BS, such as Col. Olcott's disinformation regarding the 8th Sphere. Alice Bailey wrote a great deal of such garbage.
Rudolf Steiner was associated with Blavatsky for a while, but later split off and formed his own organization, which he called Spiritual Science and which he regarded as the modern successor to true Rosicrucianism, as opposed to the Venetian counterfeit (an early form of occult BS) which became the basis for many other "occult" movements such as the Scottish Rite and the Golden Dawn.
Seen in this light, Blavatsky's "Theosophy" was intended as a more modern form of occult BS to replace the Venetian oligarchy's (specifically, probably the diabolical Paolo Sarpi's) bastardized version of Rosicrucianism, the original of which was a true Mystery teaching. The LaRouche movement has made Sarpi notorious for creating bogus teachings to substitute for the real thing, even before the real thing gained significant traction. Much of today's "science" and "math" is based on Sarpi's perversion of real science and real math. The effect has been to interfere with mankind's consciousness-evolution, which is sheer evil.
On the other hand, black magic is actual occultism, but utilized for evil purposes. (Occult secrets can be considered to be scientific knowledge, which can be used for good or evil.) However, black magic is also extremely secretive. In order to give its students the monstrous, egotistical attitude which will guarantee that they will utilize its occult secrets for evil purposes, they are required to do certain things before being given any secrets. ("Occult secrets" is actually redundant, but I use the phrase to differentiate actual secrets from Mystery teachings which were once secret but which have since been made public.) This ego-intensification must be distinguished from possession, in which the individual's ego or I is no longer in control.