I have seen these three characters forming the "same" words (I cannot think of a better way to phrase this), such as
惡夢 vs 噩夢
惡運 vs 噩運 vs 厄運
As I tried googling for the difference, I find different opinions on their meaning/usage – some argue that they are interchangeable; others claim that they are slightly different. Below is what I thought to be the best explanation I have found by far:
不祥不一定就会发生灾难, 但灾难必定是不祥的, 而这两者都很恶劣.
However, the explanation still sounds rather vague to me. In explicit, how do these characters differ in meaning/usage?
Thanks in advance!