Question about key modifiers

Hi all, there is something I am trying to do on a few macros, but I’m not quite getting it - hopefully someone out there can clarify for me.
I’ll use my DH tank as an example, but the situation is relevant to a few characters.

  1. My macro rotation uses the usual fury builders with Soul Cleave, Spirit Bomb and Chaos Nova as the spenders.
  2. I have Fel Devastation on mod:Ctrl, with [nochanneling] included on all of the other abilities to make sure that it doesn’t get clipped by other skills.
  3. The issue that I have is when I press Ctrl, if I don’t have enough Fury, the macro does nothing - just waits for the fury to be high enough to cast Fel Devastation, but in the meantime, doing nothing. I would like to change the macro so that it runs as it does now, but when I press Ctrl it runs a different macro - where Soul Cleave, Spirit Bomb abd Chaos Nova are replaced with Fel Devastation - so I could press Ctrl and still generate Fury until I have enough to cast Fel Devastation.

Is that possible, and if so how can I achieve it?

Many thanks!

Simple answer: no that is not possible.

Longer answer: WoW has the limitation that it can try ( this try is extremely important) one GCD action per hardware event. Blizzard wants you the player to make choices of donI need to use X spell over Y to generate or spend resources and explicitly blocks Macros or Mods from being able to make those choices. The choice to hold control to use Fel Devastation is one you the player has to make and once it tries fel devastation, that is your try used up for this hardware event. If you don’t have the fury well this try was wasted and better luck next time. WoW won’t let you fall back to go FD won’t work so you need to generate some fury instead. You either choose to hold CTRl to try to use FD or you choose not to and try to do the cast that is in the body of this action.

As a alternative you could create two macros. The one you already have and the one that inlcude fel devastation and another spell that will generate fury.
You can setup the first macro for example on key 1 on your bar. Then you put the second macro to another slot on the bar and set a keybind to this one with shift-1 for example. When you are firing button one and you need fel devastation you hold shift and the second macro is executed as long as you hold shift. When done you release shift and you continue with the first macro.