Let's look at an example, as that is the easiest way to understand this use of the semicolon. Suppose I want to list three items that I bought at the grocery store. The em dash is perhaps the most versatile punctuation mark. Depending on the context, the em dash can take the place of commas, parentheses, or colons—in each If you want to draw attention to the parenthetical content, use dashes.
All three are correct, but I would personally choose the comma. Oxford comma should not be used for that sentence (between "themselves" and.
Use an em dash instead of a colon when you want to emphasize the conclusion of your sentence without giving it all of the connotations that a.