I guess I'm a bit late as you did the essay today, but looking forward, especially as HSC English requires much essay writing, there are a couple of things I'd suggest.
You have a good way of writing and your language and reference to the book are very good. Your introduction and conclusion are very short and you'll need to work on this. Personally, when writing essays, I use my introduction to provide a bit of context and try to hook the readers in. If I was given this question, I'd use my introduction to discuss power itself and how it's attained, then link this briefly to the character in question. If you want an example, message me and I can do one for you quickly. The conclusion should be one of the strongest parts of the essays, so it needs to have substance. I always link my conclusions to my introductions and sum up my entire argument. Again, if you want an example, just message.
Another little suggestion is, throughout your writing, use conjunctions to link two short sentences together. You have many short sentences within your essays and I feel that if you linked them together the piece flows more continuously. For example,
One of Napoleon’s main tools for gaining power was violence. He does this by suppressing any contradicting ideas and frightening the animals. Can be linked together:
One of Napoleon’s main tools for gaining power was through employing the use of violence, performed through suppressing any contradicting ideas and frightening the animals. Not only does it make the piece flow more effectively, but you cut down words too, which makes it easier to write.
Just some thoughts - the essay was very good though