What happened to people like Xiao and MAGA seemed clearly unfair to me, losing over 1000 buildings from EQs in the matter of seconds. And to this, the devs did an excellent job of rectifying it. Now it may sound odd coming from a player who had no magic defense, but I think it may have gone too far in the other direction. So here's my suggestion

I think that EQ should be equivalent to an attack, meaning if it's successfully cast, it should do damage and destroy as many buildings as you would have lost in an attack. For example

Player A has 5 castles 100 land, 20:1 ratio. If they lost an attack then they would lose 1 castle, 20 land, and 200 buildings.
Player B casts a successful EQ -> destroys 200 buildings. It's an attack so player A goes into protection
EQs cannot be cast on someone in protection, prevents spamming just like protection does for attackers

Now this would also scale, so at 45:1 land, it destroys 450 buildings. And if a player is over 20 castles, same thing. If you can lose 2 castles and the lot of land associated, then you can lose all those buildings from an EQ.

I think this is fair for casters because it still gives them power when using EQ, otherwise I don't think many will use the spell. I think it's fair towards the recipient because it causes all the damage of a loss but with added relief and penalty.

Relief: You didn't lose the land and can rebuild the lost buildings if you have the resources

Penalty: When a player loses land to an attack, then gains it back, they also gain 60% of the buildings, meaning they don't have to build as many. So rebuilding from an EQ is more costly in that way. No direct army costs of losing soldiers from attackers, but losing GHs and Farms may cause the player to lose army as well.

Please let me know if you think this sounds fair, because I want EQ as part of the game, even though I don't use it. And as many have pointed out, they want Elf and casters to be specialized and capable otherwise what's the point.