It's not a noun, it's an adjective. You can use this reversed word order for stylistic purpose. It can often be seen in poems.

Yes, it can be poetic. "[Noun] is [adjective]" is a common kind of sentence. It is saying that something has a particular characteristic. In English the noun usually comes first. Examples are: "The sky is blue," "The night is dark," "The load is heavy." When we change the word order, the sentence is still understandable, still good English, and the meaning is the same. But the different word order is surprising, and calls attention to something, usually the first word. If someone says "the sky is blue," the emphasis is on the sky. If someone says "Blue is the sky," the emphasis is on the blueness. "Dark is the night" emphasizes the darkness. "Heavy is the load" emphasizes the heaviness. Of course, in a poem or a song lyric, an author might do this to fit the words to the rhythm or the rhyme.

That's probably more for poetic purposes, or like old English which is the tone of the movie. To make that grammatically correct, it would be ("Their hate is strong.")