Is it okay to put the phrase "in that box" after "the world"?
Yes you can! The sentence would be changed to "You take that box, and place all of the horrors of the world in that box." Both sentences are fine to use and both make sense. This is because they both function as adverbs. They are answering the questions "where?" "when?" or "how?" In the original sentence, the prepositional phrase is modifying the verb "take." It's answering the question "what?" What's happening with the box? Horrors are being placed inside the box. When "in that box" is placed at the end of the sentence, it is modifying the verb "place." It is answering the question "where?" Where are horrors being placed? In that box. Thank you so much for your question!