[Solved] How to make Freezing Breath become a spell cast on units?

[fanofdiy]

As we all know, Freezing Breath is a skill of the Frost Wyrm which can only be cast on buildings.
I wanna make it become a spell cast on units. Is it possible? Will it cause any problem?

 

[Chaosium]

Tried changing the targets allowed by adding organic units and see if it works at all

 

[fanofdiy]

Solved. Add a trigger by a Dummy unit attacking the target, then it works.