Lexical variety is good, but there is a reason to reuse words and phrases. When I saw proof of what I was already sensing; I changed my approach to writing. Tolkien‘s constant mentions about the ring inspired my change in philosophy. If you have something or someone of prime importance; you have reason to mention it or them, a lot.
I tried to limit my mentions of the mask before, but now I want more. It gives my novel a stronger center. You need to limit the items and people, you use this technique with, but it will increase the novel’s identity. Repetition aids memory, so you write the word into people’s heads. Why did ‘Bond, James Bond’ become a catchphrase? Three words and two mentions of Bond–might give you a clue.