This plugin sets a player on fire for a configurable amount of time if they type the command /diamonds.
The permission is Diamonds.diamonds.
To install this just drop it in your plugins folder then restart/reload your server.
To configure how long the player will be set on fire go to the config and by "Burn-Time (in seconds):" put however many seconds you want.
If you need any help with anything, want me to attempt to write you a plugin, or anything else, feel free to reply below or email me at [email protected]. Thanks for downloading!