I couldn't disagree more, especially with English. Only sometimes does exact word choice matter. In almost every other case, the difference between one word and a synonym is meaningless. The author only picked one over the other because they like that word more or they thought of it first or because it flows better with the rest of the sentence. That's it.
{Scrubbed}Beyond that, Pandora referred to Tedd's current sell casting ability as "use" spells, not cast them.
"You can't cast spells, but you can use them" on one page, present tense, indicating that what Tedd can do now is not casting a spell.
"You will cast it" is future tense, and the previous use of "use" instead of cast indicates a difference.
{Scrubbed}Just because I'm interpreting it differently from you does not mean that I fail at reading comprehension and I do no appreciate the insinuation.