Perhaps not so much with implementing flying animals on fire lol. however, humans should gain access to an element for magic users.
Humans gain access to the school of wind magic.
Movement speed boosting spell for a wide radius. all units gain 25% increased movement speed for the duration which would be 10 seconds.
Tornado. a targeted spell that fires in a straight line dealing anywhere from 75~125 damage for every unit hit. (may be a little op) has a cooldown of 90 seconds.
Haste. Increased attack speed for targeted unit or batallion. attack speed increased by 50% for 5 seconds. 30 second cooldown.
That's something i'd like to see.