To clarify you want (ex shockwave) to be castable from friendlies in range of aura, but cooldown tied to the source of the aura?
If I understand correctly:
Necro with Shockwave aura and three ghouls
Necro casts the ability at a nearby footman
ALL GHOULS AND THE NECRO Cast shockwave at the footman? OR Closest GHOUL in range casts?
If this is the cast you don't have to add the ability to the unit since it's completely tied to the commands of the caster.
Event - cast, then into unit group check of the closest unit (w/ matching aura buff) to the target point/unit, create a dummy, cast, presto!
Unfortunately I don't know of a way to trigger a cooldown of an ability without first casting it.
However we can simply make a cooldown with variables and remove the shockwave after the first unit casts it.
I'd use Bribe's Unit Event to detect Initialization / Creation / Revive & vanilla gui for learning the ability to detect a unit that has the aura.
Then an area check that adds units with the valid buff into a periodic check if they still have the buff and still living
Detect when shockwave(aura) has been cast by unit's in the group and remove all instances of the shockwave ability from units in the aura group adding a X second "Cooldown" variable that will tick down before adding the ability back to the unit.
I'll take a whack at this tonight and see if it's presentable.
I take it you don't see the humorous image, Grog'nar is the silly looking orc I made.
Simply give a unit you want to be the aura "source", if a unit with your aura attacks another enemy check if the caster's "source" ability is on cooldown or not, if not cast shockwave from the unit's position!
Viola, no need for fancy-smancy cooldown witchcraft.
Ah so they're treated like heroes and take reduced negative buff times then, no reduction to spell damage.
How would the AI use the blink though? I don't there is AI attached to the buff for non hero units.