From what I have seen in the previews, I doubt that the spell are really powerful. It seems to look more like the spells in age of wonders, some spell are useful only in very specific situation or Spell gives you a minor bonus with a maintenance cost too high.

I don't know why, it seems in any video game, tabletop RPG and board game, the designer are scared to place powerful spells in the game. They fear it will unbalance the game.

If this is the case for elemental, I will design a mod that will either powerup the current spells, or design new spells that will ahve much more impact on the game.