Could the passing of the illusion trait be turned off for particular spells you cast? This could be accompliced by having an ability like the "reveal self" for the cloak of Esus. You would lose the illusionist promo and get a placeholder promo, maybe passing a -10% combat penalty for summoned units to deal with the fact they are not use to summoning real creatures.
For 1.4 they could have a spell similar to phantom killer or weird from dnd. This would be a summons that requires specialization in death and illusion.
When the summoned illusion starts combat with an enemy there is a chance for the target to die from fright, depending on level and resistance to magic. Otherwise it just damages the unit normally up to 35-45% or something around that value. As soon as it finishes combat it "dies".
For 1.4 they could have a spell similar to phantom killer or weird from dnd. This would be a summons that requires specialization in death and illusion.
When the summoned illusion starts combat with an enemy there is a chance for the target to die from fright, depending on level and resistance to magic. Otherwise it just damages the unit normally up to 35-45% or something around that value. As soon as it finishes combat it "dies".