Three Mistakes to Avoid when Writing a Magic System - Worldbuilding 101 

I follow the advice said about portraying advanced tech/magic as mundane and tried to apply it to my magic system. Thus, I try to avoid going into the kind of stuff you might find in a stereotypical magic system, so nothing even remotely potentially world-ending like veritable nukes or time travel is present. If I were to compare it to modern weapons, the most anyone can wield is the magical equivalent of a small-gauge shotgun or submachine gun, though most are able to use up to a medium-sized pistol (note that these are just rough equivalents). Despite this potential power, most do not use it for conflict because using magic requires clear and preferably detailed mental imagery and focus, so highly stressful circumstances such as combat render performing offensive magic largely untenable. That is not to say that there is none, just that it is usually only used in suprise attacks or some other form of opening strike/salvo, though it never gets strong enough to function like artillery. Thus, most of magic's usage is limited. The bulk of it can be described as matter/energy manipulation, so there is telekinesis and rapid sustained temperature alterations (i.e. fire and ice in function), but output is generally low-power. This is because the energy behind magic is found in everything and yet living entities contain much more than what is not living. However, blood magic is not a thing due to magic quickly dissipating upon death, so any potential magic is typically lost before it can be utilized. Sure, excessive numbers of sacrifices could theoretically be used, but the efficiency is so poor that such is treated as little more than a means of s^^^ide so as to avoid shame of defeat and capture. It would be like detonating full-on nuclear warheads within your own nation to ensure that your enemy will not be able to use the land for anything. Because of this major limitation, the bulk of magic usage goes more towards what many might consider as support. Body enhancement is by far the most common usage, so magic users, through constant sustained usage over the course of their lives, develop bodies with greater strengty, speed, and stamina. No one is naturally a super-soldier, but there are individuals who do eventually develop their bodies into such, albeit on the lower end of such a goal. No one quite has a Wolverine healing factor, although reduced recovery times are common (e.g. shaving 6 weeks of healing a bone facture down to 1-3 weeks). Magic can be fed/used/manipulated in others in order to accelerate their healing, but that still generally requires in-depth medical knowledge. There are other "support magics" used, but the ones mentioned are the most common. Location does play a role in how powerful magic usage can be. Regions that are teeming with life tend to yield greater outputs in magic, while barren deserts see limited magic beyond places like oases. Yes, this does mean that cities can yield significant magic output, but that still depends on a lot of other factors. Regardless, because of the much greater input from animate objects, environmentalism is the norm, not necessarily to the point of being in total communing with nature (though some do practice this) but still avoiding the environmental damage of the early Industrial Revolution. On the whole, magic does not run civilization, but it is not neglected either. Perhaps the best way to describe it would be a seemingly endless stream of life hacks, where they are not actually needed anywhere but can certainly be beneficial if applied. I have been pretty adamant about avoiding any sort of power creep, but I am pretty sure I unintentionally violated that rule at least once at some point(s). Admittedly, it started from the fantasy of having magic to solve the most frustrating of the most inane things, like trying to reach for a screw/nail/nut/bolt that fell out of your grip and rolled away into the most inaccessible spot or drying yourself off extremely rapidly despite not having a towel at the ready.

check out He who fights with monsters, it Magic system is amazing

I'm building a system that's rather flexable, but the limitations keep it in check. For one thing, different cultures approach magic in different way, so to use their magic you need to understand their process. Another element is that weak spells are easy, but get substantially more difficult when you upcast. The fireball that burns some enemies is a thought, but the fireball that burns down a building needs elaborate rituals, and magical foci. Also, magic pushes at the fabric of reality, if you push on reality too hard it pushes back, or even worse, you damage reality, and let the monsters in. Finally, there are institutions designed to police magic so that realitydoesn't break from someone making giant fireballs. Magic is limited to only authorized systems.

Precisely because magic can influence so much in our world i decided to restrict my magic system to mental related powers: -Mind reading -Mind control -Sensing other souls -Hiding your own emotions/thoughts/signature -soul-transference -entering dreams and influencing them -soul absorption, splitting, etc I thought of the first consequences: -people are more aware of one anothers emotions -those in power have a greater control of their subjects -those in power use soul trasnference and absorption to change bodies before they die and to absorb other souls to gain their knowledge -those who want to achieve power must learn to control others emotions and thoughts -there is little privacy, because people can sense your emotions -in school, it is easy to cheat in tests, so teachers make tests where the whole class has to work together, if they cant share knowledge and guarantee that every student gets the material, the class fails -wars might be influenced through literal psychological warfare (a powerful "mind controler" might make the enemy army change side, kill themselves, become too afraid to fight, etc) What i do need, and i struggle to find, is a way to limit this. I've already decided that peoples inate power level depend on how big their natural tendency for empathy is, as the empathy part of the brain will be where the soul is stored. I've also determined that lots of meditation and concentration and inteligence (specially emotional) and willpower is needed to absorb other souls and not let their souls overpower yours and to control your powers and to control others; aka: only those who train alot can control entire armies. But, what would be the resource wasted? If all it takes is training and concentration, than it becomes too op. My suggestion for a limit: -certain foods and spices (literally). The idea would be, much like in Dune, that altho sensing others and being influenced by others doesnt take up much nutrients and such from your brain, exerting your souls influence over others will consume alot of nutrients. You'd need a steady supply of salts, omega 3, oxygen, iron, vitamin D, etc, to sustain your powers. Thusly, the elites of this world eat lots of fish, iron rich foods, salt, fruits, vegetables, spices from the indies, etc. Any ideas?

D&D magic is a bit of a mess. Partially because Divine and Arcane (and sometimes psionics ) need to coexist, yet the exact mechanics largely function the same. (And it's not always clear how prevalent magic users are. ) In my settings, the gods are more like philosophers. Divine power requires adherence to a philosophy rather than deity worship. Meanwhile, arcane magic is treated like a craft. An art mastered by artists. Many of whom gather in guilds to help each other perfect their craft.

Rowling didn't write the stage play, she only signed off on someone making one and endorsed it. Don't take this as defense of anything else she has written on twitter, but you screwed up by asserting that she wrote the stage play. As bad as her writing was in the Fantastic Beasts series, the stage play was obviously below what even she would have written. Again-- she just signed off on others writing such a thing because she would make money off of it. Just like George Lucas signed off on some incredibly shitty books in the Stars Wars franchise before Disney bought the franchises and decanonized that shit.

The gender separation regarding the bending is only a thing in the northern water tribe and not a general custom of all water tribes. Also, the show makes it clear that fire bending is not just destructive either. Thus everything you said about Avatar the Last Airbender is simply wrong.