Happy Worldbuilding Wednesday? Does your world have any "forbidden" magic or power? What's it like? Is its forbidden reputation warranted or not?
Absolutely there's "forbidden" magic, by which I mean it's illegal in certain places but absolutely practiced on the down-low by at least some individuals. Some of it is obviously, yes, forbidden for a reason. Most of it is more logically forbidden as "kind of a dick move" than it is "oooh spooky scary you're selling your soul and damning your bloodline!"
Curses (bad luck, ill health, loss of loved ones, loss of property, etc) are largely illegal, especially in cities like Gallecross. The degree of severity indicates what level of punishment there will be if the caster is caught (loss of like say a cow is a lot less severe than an ongoing curse of sickness for example because someone could be severely physically harmed or killed by sickness).
Mind controlling or thought/behavior influencing magic is also highly illegal because, y'know, it's depriving someone of their free will and bodily autonomy. This is why sphinxish inherent speech magic is illegal. Though of course if you use just a tiny hint in say your business advertising, it can be hard to prove...
Necromancy is a grey area. Some places have folks volunteer their bodies after death to do dangerous work like mining for certain things, going into cursed or poisonous or diseased places that a living being couldn't, dangerous manufacturing, etc. Undead in militaries has been illegal via the Cheian Military Pact for several thousand years, but use to defend a city from outside threats may be allowed on an individual basis (again, with volunteers who signed up before death). And also, a lot of healing magic draws on at least a little necromancy so it can't be fully outlawed.
