I fully concur with what @endso is saying; using apt on console with multiple repositories that are not coherent together is asking for trouble. There are lot of packages with dependencies written so that dpkg thinks it can fulfill but end up with conflicting requirements. And if something does not cleanly install then adding --force will just make the install succeed without pulling in needed packages...

And regarding the elf you suspect that's burrowed into your device, yes; in fact there's a whole elfin family living in there...