Instant-cast a spell on multiple units.

[Blah17]

I have a bloodlust-based ability that I want to be cast on every footman in an area when they are near enemies. What I have been doing is giving the Bloodlust to the footies and having it self-only on autocast. Problem I have with that is the footmen need to stop to cast it on themselves, which is a significant problem in my map. Having the bloodlust up constantly is also not an option because the map requires that the footmen are running at the same speed as the other units until the battles begin.