emacs can be a surprisingly comfortable text mode epub reader too, via nov.el¹ which has been discussed here². If you use a GUI emacs build you get inline images and other goodies, but starting emacs with -nw can be a reasonable solution for quickly checking a book in a term.

Note: You don't have to be a full-time emacs user to use nov.el.

¹ https://depp.brause.cc/nov.el/

² https://news.ycombinator.com/item?id=21426315