Arts of Oblivion

The Arts of Oblivion is a brand of dark magic practiced by the people of the Nether Reaches. It allows the user to manipulate the evil elements of the Nether Reaches and a mysterious power called Oblivion, which Pugna often speaks of.

Description
The Arts of Oblivion draws its dark power from the nether energies of the Nether Realm. It's unknown what this Oblivion is, but it is often used as a metaphor for death, a strange controllable power, personified as an evil force of destruction  and a source of power by Pugna. Regardless, the Arts of Oblivion focus solely on death and destruction. A user of the Arts of Oblivion must "become Oblivion" in order to master Oblivion. What this really means is unknown, but it might mean that one must become an extension of its power to master it. With this dark mastery, they can channel the powers of the Nether Reaches even when they're far from it in the surface world, which might explain why it is called the Nether Reaches.

Pugna claims that all magics have their source in the Nether Reaches. Aether (also known as void and nothingness) is an essential ingredient in the arts of the arcane, including the Arts of Oblivion.

Uses
Encompassed by the Arts of Oblivion includes the ability to manipulate the emerald fires of the Nether Reaches, which is powerful enough to reduce anything into ashes, be it a living thing or a mighty structure. Magical augmentation is also within the scope of the Arts of Oblivion.

is a spell that summons the fires of the Nether in the form of deafening explosions to incinerate the caster's victims and targets. It can be cast on the ground to destroy anything in its wake or inside the target to destroy them from within.

banishes its victims to the Nether Reaches, causing them to turn ethereal. This renders them unable to affect or be affected by the happenings of the material plane, but they're still susceptible to magic and spiritual attacks.

Apparatus
The previous grandmaster of Oblivion once had a porphyry wand and an amulet in his possession. It's possible that he uses these items to work his magic and channel his powers.

A can be infused with Nether magic to turn it into a stationary emplacement that fires bolts of energy at nearby casters who uses their spells in its presence. may be an item related to the Arts of Oblivion, given that it can also turn the user ethereal, just like Pugna's Decrepify spell.
 * Besides Pugna's default ward, there is also the Draining Wight, a ward of uncommon origin made of bones and spirit with a liminal existence between the corporeal realm and an unnamed spiritual realm, possibly the Nether. This ward draws its power from the Nether Reaches to drain the lifeforce of its victims.

The may be related to the Arts of Oblivion. It was once owned by an Eldritch, of whom we know absolutely nothing about, besides being a powerful entity.

The is an article of jewelry that was once used to channel nether realm magic.

Practitioners
Among the Grandmasters of this dark art, is the most notable practitioner of this brand of evil magic. Even when he was a year and a month old, he was already able to use the fires of the Nether, but only in small fire-gouts that were deceptively devastating. His skill was further honed in the previous grandmaster's academy for the Arts of Oblivion.

has learned Pugna's magic during his captivity, using it to augment his body and poison.

Critics
rejects the Arts of Oblivion and seeks its oblivion, likely because of how effective it is against spellcasters with its infamous Nether Ward.