Remember, that if you use a dummy to deal/cast the spell, the bounty will be gained by the dummy, not the Hero itself you know.
Unless, you have a system that relates a Dummy with the Caster ?
Okay for example, this Hero has an ability that when it kills a unit, it will gain 2 STR.
Let's say Rubick own this ability (example), when it uses the ability, the Dummy will cast Storm Bolt, thus killing the unit, right ?
In the event, we would refer to (Killing unit), right ?
It should be the Caster but when the Dummy cast the spell, it's the Dummy who has +2 STR which is absurd.