Spellweaving

Spellweaving is the ability for a rare few individuals to manipulate normally inert arcanic energy and manifest spell effects through use of their body and brainstem electric impulses. Spellweavers are scarce in Tau Elpis , as thaumium must be metabolized in-utero for this ability to manifest.
It is estimated that barely 1% of the population of Tau Elpis is able to spellweave. The Boshaari Council officially claims that 5% of their species are "fae-touched" (i.e. spellweavers), but this figure is disputed. As there are no ley lines in Tau Elpis, and the background arcane field is weak, biothaumic amplifiers are necessary for meaningful spellweaving. Those amps are an invasive piece of surgically implanted magitek , and cause physical and mental strain after prolonged or repeated use.
Spellweavers channel arcane energy through their amp interface using an internal spell engram. Most speak incantations to maintain focus, but it is not strictly necessary. Once the spell is woven and manifested, a metadimensional thread perdures from spell to caster until the energy fades, which can be traced using specialized spells or magitek devices.
There are two core philosophies of spellweaving. Arcanists are casual and versatile. They preweave their spells after resting by loading them from "grimoires" into their biothaumic amplifiers. Magisters, most common in the Boshaari sphere, are even fewer in number. They spend decades hardwiring their minds around a few specific spells, allowing immediate and unprepared casting at the cost of flexibility.
Psionics are arcanelike effects, such as cellular healing or telepathy, that appear without traditional spellweaving knowledge nor amplifier use. However, those are not considered spellweaving as they rely on another, poorly understood mechanism. Psionic potential is linked to Psionic Metadisease and, opposite to spellweavers, psions requires biodampers in order to avoid strain and burnout.