'Disease' that Spreads Amongst Friendly Units? (without periodic trigger?)

[Gnuoy]

I'm trying to devise a spell that is cast on an enemy unit then will spread to nearby units friendly toward the original victim, if that makes sense.

There are old recommendations on this forum that involve a periodic trigger but I'm worried that is needlessly taxing by running a trigger so often.

Maybe something that adds friendly target disease cloud ability to a unit but puts it at -11,0 on command card or w/e? Maybe it's removed after sometime?

 

[Pyrogasm]

There are old recommendations on this forum that involve a periodic trigger but I'm worried that is needlessly taxing by running a trigger so often.

This is not a concern. Many such triggers? Maybe. One? no.

The disease spreads from unit A to unit B. Does B suffer the same effects as A, or is it different for a secondary target? If B is the same as A, can B potentially spread it to unit C, or can only unit A spread to new units?

 

[Gnuoy]

yeah i think spreading A to B, back to A and to C would be fine. Possibly to place value on dispelling.

There are a lot of other periodic event triggers but only every like 90 sec or so.