Awww...who's a good little spell...yes you are...
Nature of Magic:
Everyone who has witnessed a spell go awry has probably heard the phrase "the spell had a mind of its own", Voskomancers, sometimes called Spell Herders, will tell you that "yes, they really do". Voskomancers believe that spells are living things -- sentient creatures composed of pure energy with their own needs, wants, and preferences. Spells must not be 'shaped' or 'commanded', as some mages claim to do, but rather must be carefully husbanded and coaxed into acting in the way you want.
Method of Casting:
Each spell a Voskomancer intends to cast must be carefully stored in a vessel -- a tiny box or cage designed to comfortably hold that spell's power. When the time comes to cast the spell, the Voskomancer must open the vessel to let the spell out, then instruct the spell as to what he desires it to do, explaining the situation, the desired target. why it would be a good thing for the spell to do as he asks. Any Voskomancer will tell you that spells are skittish, flighty creatures, and must be treated with the utmost care and should only be addressed in calm, soothing, respectful tones. Of course, to a lay observer, Voskomancers usually look like they are talking to thin air.
Pages in a Voskomancer's spellbook resemble drawings of complex mazes. Voskomancers refer to these as 'habitats' and insist that each must be carefully drawn to match the preferences of the specific spell it is meant to house. Preparing spells for a Voskomancer consists of tracing the route of the maze, leading the spell out from the page where it can be coaxed into a vessel for use.
The Limit: (i.e. Why does this guy have Vancian spell-slots?)
Spells are flighty creatures and tire easily. Much like trying to walk a pack of dogs, an inexperienced Voskomancer cannot handle more than a few spells in a given day, or else he risks the spells running away from him. Spells that have not been with the Voskomancer long are less prone to accept his orders, and will not come out of their vessels more than once before demanding their rest. With time and experience, the Voskomancer and his spells become more accustomed to each other and he can bring more with him and coax them into service more frequently.
Breaking the Limit:
A Voskomancer who has exhausted his daily allotment of spell slots finds his spells have become too tired and unwilling to follow his orders. He can still, with much coaxing and negotiation, get the spells to do what he wants. Each time a Voskomancer attempts to cast a spell after reaching his limit, he must make a Charisma check, with a penalty equal to the spell’s level. On any failed check, the spell has been angered at being awoken and runs amok, creating a Wild Magic surge. A spell that has gone wild immediately returns to its 'habitat' and is lost from the Voskomancer's list of prepared spells. It can only be prepared again after the Voskomancer (and his spells) have had at least 8 hours of rest.