make dark fire

How to make dark fire that appear after pressing a key then disappear after making the order

You could do this:

var darkfire : ParticleEmitter;//Or GameObject, or whatever!

function Update(){
   if( == false;){ = true;
if( == true){ = false;

This is just the main code, add some if’s or some cases to it to make it more advanced
If you’re using legacy particles replace darkfire.gameObject to

darkfire.emit = true;