targeted aoe for specific combo?

Hey, so I had this issue earlier, and was given a solution that worked well, but affected all my combinations- I never was able to successfully make it specific to ONE combination though.

Here's what I'm trying to do- when I hit my keybind, I want it to activate Rain of Fire on all three characters so that I Can target it on all three windows, then go back to normal once I've activated it, but I need to know how to do this for only one specific character combination.

I'm kinda a dummy when it comes to working software, if I could get a step-by-step answer, that would be amazing! Thanks in advance, again

[lax]

To make the actual key, use the Mapped Key Wizard and select "Straight Key Broadcast Plus Click" as the type of key to set up.

I need to know how to do this for only one specific character combination.

Create a Key Map, and assign this Key Map only to the given Character Set. Put the new Hotkey in your new Key Map