Need help with special weapon features

Hi everyone, I need some help with special weapons and armour for my new mod, inspired by Arithain's mod, Charter. I would like to make a weapon that when you kill someone with the weapon, displays the death message "<TargetName>'s existance was repourposed by <AttackerName> using Charter Spelled Blade. Then when they click respond, they are banned from the server.

Thanks for your help.