A simile is when you compare one thing to another by using <em>like</em> or <em>as</em>. There's an <em>as</em> in the second one "as easily as sliding a knife...".
A metaphor is when you say something <em>is</em> something, not just like it. "[his] face became a white sheet".
An allusion is making a comparison to something the audience knows about, like comparing a rivalry to rock paper scissors (this particular one implies the speaker always wins).
No essay, but consequences are not always fair because those making the judgments are wrong at times and don't see the full story, therefore making the one who might actually be innocent suffer.
