I have been reading fiction for five decades. If I every write a story then the grammar, syntax, and usage will be obsessively correct. Beyond that, I make no promises.
NB - Someone convinced me that the meaning of decimate has changed. Widespread devastation short of total destruction is an acceptable definition. Sorry, I'm old.
Entering ranting mode:
'Prophecy' is a noun: a prediction, while 'prophesy' is a verb: to utter a prophecy.
Oh, and I will leave it up to you to study the difference between 'apocalypse' and 'armageddon!' as well as the difference between 'loose' (the opposite of tight) and 'lose' (the opposite of find).
While I am at it, I have to share that while 'per se' has meaning, 'per say' does not. Look it up.
End ranting mode, slightly shamefaced.
PS - As the father of someone making a career in Equine Science, I can tell you the difference between giving someone 'free reign' which is meaningless, and in giving 'free rein' which is idiomatically correct.
PPS - One more thing: To 'toe the line' which means to stand with ones toes aligned with a real (or imaginary) line, allowing people to be physically (or metaphorically) aligned with a military precision. This should be contrasted with 'tow the line' which has meaning only in the mind of its writer.
Someone finally explained part of the epilog to me. Harry was drunk when he named his son Albus Severus. His full name is Albus Severus Tom Vernon Potter.