Arch Users: please use the AUR: https://aur.archlinux.org/packages/mcomix3
The attached .deb file has been tested on Debian 13 Trixie (warning: it will remove the old mcomix, if you have it installed).
Changelog:
Fixes reverse scrolling: now, when scrolling up from the first page of a comic, the previous comic is loaded at its last page.