Enemy strategic spells cast on my cities don't generate much of a notice that they're there. Occasionally I will see some black vortex-y thing above a city, but it's not immediately clear what this is or what spell is being cast. IIRC, it turned out to be two grips of winter that looked like one spell.Other spells go completely unannounced and undocumented, including that one that permanently raises unrest (apathy, I think?), and one spell whose name I still don't know that littered my empire with fire elementals and ignys. (I REALLY want to know what spell that was )