Because its not a obvious sphere choice, i think it would be good to raise the subject of a additional form of magic. Persuasive magic is a brand of magic in itself, the art of twisting and manipulating someones mind to make your will. I've detailed a few points below.
Practical UsesHow great would it be to have someone agree to do whatever you said and bend to your whim? A few exploits of what persuasive magic can achieve.
> Extort information truthfully from people about subjects, and scour their minds for details. Being so invasive to a person's privacy might not make you particularly popular.
> Erase mental evidence via a little wave of the hand or a complete mental 'reset' to wipe away their mental state, which on one hand might cure a dwarf of a failed mood, but also make them forget how to function for a number of years in a catatonic state until they recover.
- "These are not the dwarves you are looking for"
> Convince people of a suggestion even if they are bound to likely become a criminal or hurt themselves in the process with unwavering forced loyalty. People like the local lord? Just dominate their minds and then treat them with utmost cruelty to build a 60 z level tall statue in your honor.
Stupidity & WisdomSuch persuasive magic is most surely going to have some kind of target audience. Which is why i mention the weak minded as a easy avenue, a poorly educated hamlet villager without personal statistics on their side is going to be much easier to convert than a trained academic specialist.
> For a contractual price of magical energy (whatever form that may take, i always fancied losing intelligence stats temporarily yourself as a consequence for doing this), enlist none tag explicit semi sapients or intelligent beasts/townspeople with low intelligence or [SLOW_LEARNER] statistics to join you as companions in adventure mode, and as non-citizen residents (as to say applicable to take a tavern room, if they are a slow learner upon citizenship the room is released and they join as willing 'minion') in fortress mode. However this means that you will probably have to have a specialist in this kind of magic in-house or employed as a land holder/late game noble (perhaps the dungeon-keeper could make a return?).
> Higher mastery of persuasive magic works better on more intelligent beasts, but there is a ceiling limit to how intelligent a creature can be in relevance to the magic wearing off over time or being repelled or even countered by novices attempting to take control of a dangerous creature such as a dragon or a megabeast.
> This magic works in reverse for bewitching extremely stupid dwarves to the will of the caster, such as switching sides in a battle or drowning themselves by walking into water so that a creature like a pond grabber may 'feed' akin to a siren's song. The powerful effects of persuasive magic may distort the victims image of the user, such as a night troll post spouse transformation appearing as a handsome partner or a terrifying monster drawing in a adventurer like a enormous angler-fish with a deception.
> Like necromancery, having a talented magician such as a persuasive magic specialist carries inherent risks, given the control to dominate and control the weak minded as well as slights of hand to achieve what they want (such as constant arguements over taking too many lovers, who a small portion may be other fortress dwarves wives, leading to grudges) in a loyalty cascade, they definitely have the upper hand in convincing numbers to join, even if they are unwilling.
Nature and maliceThe forces of 'good' and 'evil' while never quite a clear line have quite distinct differences between one another by the way that they function. And this is a potential avenue for this brand of persuasive magic to branch out and affect other new things.
> The forces of evil employing [EVIL] aligned creatures such as trolls, harpies and ogres but permanently enslaving them as minions to conduct manual labor and military footwork, while on the flip-side, elves use [GOOD] tags to entice unicorns and other such fantastical creatures into tolerating their presence. Both of them either naturally or employ/have experts in both the nobility and academic application to help make this happen without fuss or contacting a outside wizard to do it for them.
> Evil entities torturing the mind with persuasive magic in order to extort more forcefully.
> Other tags such as [NATURAL] and [SUPERNATURAL] taking great precedence to different types of 'persuasive magic' rooted in druidism/occultism, generally while the end result may be the same, the subjects differ a little bit.
- Typically [NATURAL] magic or druidism would work like as described by threetoe in allowing conversion of beasts into talking members of society, often travelling alongside people of that entity and communicating telepathically between each other
- Occultism on the other hand or generally tags that aren't explicitly linked to a form of persuasive magic is a much larger field, in this line of magic [SUPERNATURAL] creatures themselves may have magical potential or even crude spells of their own to use, which to a budding sorcerer may be useful to use or learn from by making the creature teach it to them and emulate
Thanks for reading, i hope you intake some of the points i have for this suggestion.
TL;DR : Wololo