Can someone make a sponge plugin for me that runs a command when someone gets killed?

[Cahsew]

I am making a server with some mods and I want a plugin that will run a command when someone gets killed or dies. It will run a command that makes the killer bigger in size (using the pehkui mod) and the victim smaller.

I don't know to much about plugins so if you are interested, you can name the price.