Users of Arts are known as Casters (not to be confused with the Operator class). As a matter of fact, Operators that are not strictly of the Caster class are capable of using Arts, notably Earthspirit and Istina.
Arts come in various forms, ranging from damaging projectiles, destructive effects, wound healing, and augmentation, but a Caster can only use one particular type of Arts which depends on their mindset (e.g. Talulah can only use fire Arts due to her violent past and FrostNova can only use ice Arts due to being raised in the harsh, cold tundra of Ursus).
Arts vary in effectiveness, determined by the Caster's willpower and mindset. Simple Arts can be casted with the Caster's mind alone, but are limited by their range and effectiveness, and as such, are typically only used for oneself, as seen with Blaze's tactical chainsaw and Skullshatterer's grenade launchers. Complex Arts, however, must be casted through incantations – as such, Casters must not have any form of speech impairments and continue chanting to maintain the Arts' effectiveness; the chanting came in various forms, typically songs as seen with FrostNova's ice Arts.
Not every Terran can use Arts, at least in a functional form. Many non-Arts users rely a lot on Arts amplification devices to enhance it, such as wands and chips. The talent of Arts is also dependent on races; for example, many Sarkaz are proficient Arts users though it comes with the price of very high tendency of contacting Oripathy. There are some Arts that are limited to a certain race, like the Dracos' extreme fire Arts that could consume their life energy as in the case of Talulah, Reed, and her sister. Deities/Titans and Seaborn lack the proficiency in Arts; however, the former use some sort of supernatural, magical power while the latter enhance their biological traits such as their hive mind.
The strongest Arts user known to date in history is the Leithanien Witch King, who had mastered all kinds of Arts. Other notable powerful Casters are mainly Sarkaz such as the Nachzehrer King, the Prince of Blood, and Logos.
|“||A technique that can alter matter or consciousness by stimulating the energy inside Originium, harnessing it to manifest Arts.||”|
|—Loading screen tip|
The Infected are able to use the Originium within their bodies as a medium for their Originium Arts, but this comes at the cost of rapidly accelerating their Oripathy and can even backfire when this method is used against the Infected themselves; the Witch King's loyalist Casters are known to have done this.
In certain occasions, one's Oripathy can influence their Originium Arts' effectiveness, but the Arts potential of non-Infected casters can match the Infected's Originium Arts even when using their devices.