Question Plugin that runs a command on kills?

Hello, I am looking for a plugin that would run a command on the specified player who got X amount of kills. For example, if a player got 5 kills then a couple commands (configurable in the config) would run, like /pex group Test user add Player, and like /broadcast Player ranked up!, or something like that. The plugin would also have to make sure that they can't kill the same person over and over, too. Thanks for your help and PLEASE let me know if you know of a plugin like this, thanks again.