[Spell] Flying Units Problem

[ShenLong Kazama]

I made two units, a normal melee one and a flying transformation form. The transformated unit can fly but still ground units can attack the unit. How can i make a proper flying unit which cannot be attacked by ground units when it transformed?

 

[Pharaoh_]

The flying form, go to the field "Combat - Targeted as" and check "Air" (untick Ground).

 

[defskull]

And since this has been asked...
Pharaoh, what's the use of these actions ?

• Then - Actions
  • Unit - Remove classification of A ground unit from (Triggering unit)
  • Unit - Add classification of A flying unit to (Triggering unit)

I tried to remove the unit's classification of ground unit and add flying unit classification to it, but still, fails (my Footman still attacks my changed classification unit)
So, what does this action truly does ?
I'm assuming it is manipulated to make different between filtering unit ?
Like (Matching unit) is Magic Immune, eh ?