To those who see in the spiritual world but psychological dispositions and of 'philosophical principles' mere mental concepts, there are apologetics that are offered for Crowley's own clearer views as expressed in such a 'textbook' as his Magick in Theory and Practice.
There (and elsewhere), he claims clearly not only that one is to seek one's own "Holy Guardian Angel", but also claims that his (not everyone's!) is Aiwaz, and that, further, this is the same entity as Satan.
Certainly, I would further suggest, his view is that this Aiwaz is a different being to Christ (as an example).
My quote - as any quote - was taken out of the full context of the book, but not out of context in terms of its meaning within that book - or within his overall Opus.
The question of whether or not he was a 'satanist' is of course marred by how this term is in various ways understood by each of us, so allow me to outline, outside of his own peculiar writing (that I have done in my post above), another manner in which he can be so viewed.
For this, I will take as given the existence of a spiritual world, and that further this world is inhabited by a pleroma and legions of spiritual beings. When invoking or in other ways involved in magical or spiritual work, one works in consort with that world. The 'satanist' will be one that works in consort (whether awake to it or not) with beings of a particular kind that seek to either force humanity's premature development or retarding the same.
An instance of seeking to force premature development is to seek for someone to engage in an activity for which they have not, as yet, properly developed (as very simple analogy, with similar shock value, is the sexual). As a consequence, a stifling often occurs, unless the person is able to overcome the assault to their being in ways more difficult than had they not been so exposed.
Retardation is equivalent to engaging in activities in which one may lose oneself to the delights of past experiences, without the effort supported for further growth.
These two are the two extremes I mentioned in, also, my previous quote when making mention (as does Crowley) of Satan (or Ahriman) and Lucifer respectively. In contrast, one may compare an appropriate support for efficient and healthy development of all one's faculties and organs - such, I would suggest, is reflected in what some esotericist view as Christ or the Light of the Sun.
If one looks at the body of work stemming from Crowley (irrespective of what we know from various biographies of his personal life), what seems apparent is that he seeks to consciously work with the spiritual realms, conjuring and bringing to submition those he invokes, and lacking tolerance and compassion for both fellow human beings and spiritual entities.
His focus appears to be to bring to bear his will upon all, and only if and when confronted with another being with a will stronger and more bossy than his would he 'submit' to its bend. Quite at variance with will under the balancing power of Love. These two, Will and Love, equal only at a very sublime spiritual level, and at that level equal also with Knowledge, infused with the crowning radiance of wisdom and understanding.
In contrast, then, there is a sense that a whole direction of development and intent is for domination, accelerated (but as false and inappropriate) development, and a subjugation of the spiritual sublimated to the forces of egotism. And that, in a nutshell, reflects, at least to my view, a form a satanism.
Something, incidentally, quite distinct and different to beginning to understand the gods Pan or any other he (and others) may inappropriately overlay in correlative fashion - something that he certainly took from the GD and further expended, masking further intrinsic differences between the numerous impulses working themselves in myriad forms.
How does this apply to tarot? Apart from the comment he makes (and that I quoted above) about how this is depicted in card XV, his correlative overlays are going to be reflected and included in the depictions drawn by Freida Harris. So, for example, Strength has become other than Strength.