I'm not at home so I can't post a screenshot, but in my current FE game, the AI definitely used a strategic spell on me.

As soon as I declared war on a nearby faction, I saw a spell animation above one of my cities.  However, my issue is that I couldn't tell what spell had been CAST.  There was no icon in the city description or on the overworld map indicating what enemy enchantment was cast on it.

In the end, by individually hovering over the different numbers in the town, I figured out that the enemy AI had cast the spell that give a penalty to Unrest (I forget the name).  When hovering over the Unrest in the city, you could see the negative modifier from the spell.

My issue is that:

1) There was no notification that the enemy had cursed my city on the right hand event bar.

2) There was no way that I could see from looking at the city that I'd have any way of knowing that it was cursed.

3) The only way that I knew the city was cursed was because my screen just happened to be near that city when I declared war and clicked the "Turn" button, at which point I saw the spell animation.

Earthquake spell is too strong and devastating. And while AI doesn't use it Human playercan use it frequently, which wipes AI to the grownd. Earthquake should be weaker, more expensive and available to AI.

I've definitely had antipathy cast on my city before. And, AI has no problem at all fully using city enchantments and unit enchantments.

The real issue is noticing when it casts strategic spells on you. 

If the AI started using direct-damage strategic spells like Vetrar's Howl, pillar of flame, falling star and Tornado, the "AI is too easy" complaints would become much more rare. Pretty sure they've NEVER used one of those on me, though of course it is possible I just didn't notice. 

I have seen the AI use strategic spells on me, although I'd like to know what they are as I haven't memorized the animation.

I agree. More warning and pop-ups required when AI uses strategic spells against player.

I  just nailed two major armies on the AI's own ground and sacked three cities in a row with no single malicious strat spell cast on my troops.

And that particular AI faction is quite powerful. So it ought to have enough spells and mana to lay waste on them... Very weird that...

I've had grip of winter cast on me - and got a message to that effect

Seems to me tha AI usually doesn't have enough manna to do much, fortunatley for me

Maybe ion higher diff levels in which the AI gets bonuses and cheats in other aspects anyway. But to REALLY FIX this, the AI has to be implemented in a way it actually manages it's ressources in sensible manner!

Maybe. But it should have been so from scratch. Though I believe the others they had grip of winter or such cats on them. But I am yet to see something similar...

See, that's what I meant...