I apologize if this is a bit of a necropost. I recommend AndrOpen Office and MS Word. I installed at least half a dozen different word processors and these were the only ones that had support for custom fonts (a must for me). They were also two of the few that did not give me a headache.
AndrOpen Office has to be installed directly from the Google Play Store, if you have access to that. It also requires a lot of setup with the GUI but should be fine once you have it to your liking. I recommend getting the $5.99 Professional Pack to get rid of ads, support Dropbox/Google Drive, and support further development.
Word is a nice, clean interface and would have been my go-to if I didn't need custom fonts. I'll be getting Office 365 (about $6.99/month at most) to enable those and get the 1TB of cloud storage.
Both required a little bit of optimization to deal with the slow e-ink refresh rate in a way that isn't distracting to me, and occasionally your settings may get defaulted so I recommend screen-capping them for reference.
As a writer/editor/formatter, I didn't like any other available word processor on Android.
I recommend anyone reading this check out
Max3: Tips & Tricks and help grow that thread.