Red Orb (Sphere of Prohibition)

In most templates, a warrior can easily transform into a quite decent mage if needed, thanks to upgrades and artifacts; moreover, every warrior gets an elemental skill at level 4 and wisdom at level 6. At the same time, it is problematic to turn a mage into a warrior – they rarely get armor, offense, or tactics, which are extremely useful in combat when there is a lot of melee. In addition, warriors receive logistics much more often than mages (there is an exception here – battlemages, but this does not change the overall picture). The above is what leads to the fact that fighters rule, not mages. Banning the "ball of light" spell doesn't change much, as evidenced by the Warlord Tower.