Really quick, check out Vim for WordPress: https://danielmiessler.com/blog/vim-wordpress/
I was wondering if anyone had created a Vim plugin for editing content in WordPress, maybe using the Ace editor. But then I stumbled across the above article.
That, in my opinion, is a much better option than trying to integrate a Vim-esque editor into WordPress. While I love WordPress, the interface can get a bit cumbersome at times and this eliminates that and allows you to focus on the writing.
Vim can be very tough to learn, but for those who know it already, this provides a great way to further use them l33t vim skills!