For some reason, factions doesn't want to work on my server even though I have that mcore plugin. So how do I get the old plugin? You know, where you can do /f who instead of /f p (playername). Also, it has to work. I know some people are going to say just to download the earlier version, but it wouldn't work on a 1.7.10/1.8.1 server.
Just search around and try to find the right factions plugin. I don't know much about factions plugins or factions in general so that's all I can say