Tientai,
First of all, when cast Iching, we need to focus.
When focus on the question, your soul (brain) would think of some event, some word, etc.
And surprisingly, the guas follow your thinking and focus.
In this sense, what you do already materialize in the focus itself, and yes the outcome depends on the karma (your thinking, your fear, your attitude etc).
Even when you think negatively about a thing, the guas itself is negative.
That's why a good FT cannot FT himself because his mind affects the outcome.”