Question

Which rhetorical device would you use to create a feeling of unity between yourself and your audience?

Answer 1

The rhetorical device you would use to create a feeling of unity between yourself and your audience is first-person plural mode of address.
Using the pronoun we will include both yourself and your audience and create a sense of oneness, so to say. You are all united, which makes your readers feel closer to you as the author.

Answer 2

First person plural mode of address.  Hope this helps :D