KFactions and PEX

I just made more worlds for my minecraft server, and I made a faction world. I am trying to show the faction name in chat only in the factions world. For the other worlds, I use the message-format option in pex. I tried to show the faction names in chat, but my message format for all other worlds gets messed up. When I try to do this, I use essentials chat. Here is my essentials config:
http://pastebin.com/LxfYSZRv
and here is the faction plugin I'm using:
http://dev.bukkit.org/bukkit-plugins/kfactions/
Thanks for the help.