"Is it true she is a witch?" (1.249)
This question surrounds Ultima all through the novel. So, is she a witch? If not, what makes her different from the brujas or witches that do come up in the novel? And why does it matter in the first place?
I had been afraid of the awful presence of the river, which was the soul of the river. (2.36-37)
Here's a note Anaya plays over and over again. With the supernatural, comes fear. The people accept the supernatural, but they don't necessarily understand it. This lack of understanding makes them afraid, and it often causes them to lash out against the people connected with the supernatural, like, say, Ultima.
Ultima's spirit bathed me with its strong resolution. (2.343-344)
At different times in the book, the power of Ultima and other supernatural occurrences are compared to whirlwinds, said to "bathe" people, and cause crazy powerful physical reactions. It's as if a supernatural act or gift bears both spiritual and physical properties (kind of like the way people see things in nature, sometimes).