The Elemancers are an elite cadre of masters of elemental magic who serve House Illistim. They were founded centuries ago by Meathrix Veythorne Illistim, whose family has a long and distinguished history in it. One of the branches of the Illistim state, they are selected individually by the Argent Mirror every few years, being drawn from the pool of top researchers in wizardry and planar studies. They are the only branch which always answers directly to the Queen, obeying her sole command without any internal command structure. They are a highly autonomous group of practitioners who receive state resources to conduct their own work, and might go years in that role without being called upon to serve the monarch in any important way.
However, they are required to do whatever is asked of them, which involves any number of roles. They are sometimes used for diplomatic missions, or research interests of the state, but they are also called upon to serve as bodyguards or perform battle roles. Their membership has a diverse background, whether the mass tilling of fields, or the summoning of legions of elementals. They are all masters of "applied" elemental magic. There are even Masters of Lore, such as Vothurre Veythorne Illistim, within their ranks.
While a highly prestigious role in the Illistimi state, there is something of a conscription aspect to it, as the recipient of the honor is essentially not allowed to decline it. Some Elves may not wish to be servants of the state for whatever reason, despite the high levels of funding for whatever else they wish. Unfortunately, they would be insulting the Queen, and affronting House Illistim itself. It would be something akin to "draft dodging" in Ta'Vaalor with respect to the cultural expectations at play. Those who have done so in the past were subtly cast out as a pariah over the years, their resources and opportunities drying up and their reputations ruined.
"Illistim Culture - Part II: Branches of the State" - Haethera Illuvassas Illistim (5109 Modern Era)