I shall attempt to answer the common issues that people tend to have with the forbidden magics. Namely, I will address why they are in fact, forbidden and why it is imperative that they stay so.
Previously, Mind magic was kept under control with the application of wards as well as the strength of will of the target. This isn't really the best way to control the power. Mind magic allows for the influence and outright control of the minds of others. Without the Glyphs that the Emperor (cursed is his name) forced in place, it is very difficult to sense the use of mind magic. Thus, mind magic could be used to influence elections, subvert criminal proceedings and other such malevolent things. The Tribunal realized that if we are to have peace, we must push for equality. As such, none should subvert or enslave the mind of another.
Demonology was always a twisted version of Summoning. Rather than summon beings from the Aether (a neutral plane of spirit and thought), Demonologists summon beings from the Void (a plane full of beings that utimately wish to corrupt and destroy our world). The implications of this should be as obvious as can be. Ours is a world that was invaded twice. To willingly open ourselves up to beings that wish to harm us is not just folly but is in fact suicide. It must have been with a heavy heart that the Tribunal ordered the destruction of thousands of ancient tomes on Demonology but, it must be done. There is simply no sense in calling beings that wish to harm us.
Necromancy is a complicated and thorny issue. We have all heard the tales of Lord Terris the Black and his Black Legion. We heard how he fended off the Elohim alone and used the dead to bolster his own ranks and thus raise an army of his own. Still, Lord Terris is a single man against a long and brutal history of Necromancers who enslaved the bodies of their enemies even after death. Furthermore, there is the fact that the risen dead often possess appetites that are fowl at best. It is well known that the dead crave the energies of the living. Further still, there is the matter of the fact that all necromantic magic is tainted deeply by the void. Thus, like demonology, the necromancer is actually an emissary of the void. His goals are actually the goals of the void.
Thus, I conclude that the Tribunal was right to ban the use and teaching of the aforementioned magics. We live in a hostile universe and there are a great many worlds and planes that would wish us harm. There should be no tolerance for those who would stand with our enemies. The Necromancer, the Mentalist and the Demonologist are traitors and deserve whatever just punishment the Tribunal wishes to dole out.
— Lady Adelade St'Claire