I tried to use Eagle king and shockwave and it worked very well in early expansion.
Script: airshield/attack one turn/shockwave/attack one turn/shockwave/cast spells.
The Eagle King is actually a very good combat mage as he got armor, awe and high defense. If you use him in a standard bombardment fashion he will quickly build up fatigue due to his armor and with ranged spells costing more fatigue. So to use him most effectively as such you have to exchange his armor for something else. Pretty costly.
To ensure his safety I built 5-10 Tempest Warriors (75% shock resistance) set on guard commander.
After a couple of turns I had 5 Eagle Kings just charging in and obliterating everything.
After more experimenting I found out that they of course could forge themselves an amulet of missile protection (const2) each, eliminating the use for air shield spell. So I rapidly exchanged it for charge body; that worked exceptionally well. If I wanted I could also let them forge weightless tower shields getting their defense up to 22, and with all the experience they gathered from all the kills, they now had a cool 24 defense.
The forging is not needed of course, but it helps as after a while you want to go after bigger armies without backup. And air gems is not a problem for Caelum.
Note the minimal research and that I had no losses. The stakes are high of course as each mage cost 400 gold. But if you do it right and choose your targets carefully it will work. Try it yourself, there are plenty of more to learn from this winged dude.
Next up, another combat mage.