Phage (MARDEK)

Phages are insectoid monsters from Belfan which strongly resemble bacteriophages. Like most monsters on Belfan, they are not truly alive, but actually a physical manifestations of Miasma given form by the fears of sapient beings. For some reason they are usually weak to the elements of Aether and Fig. Monsters with a vulnerability to one such element are usually creatures that are almost purely an expression of the other, respectively a mind or soul without the other half. While it's not rare for insects to be metaphysically inferior, insectoids of Belfan don't have this weakness. It's possible that their weakness stems from having a nervous system that's overly attuned to magic despite its simplicity, making its psuedo-consciousness an antenna for psychic and spiritual influence. Phage crystals have applications in alchemy and engineering as a source of magical defenses.

Anatomy
Phages have six legs and a set of pincers at where they meet. Sticking straight out of there is a tail/stem/body made of equally sized segments, which ends in a crystalline object that's used to cast magical powers, and also defends them from magic in general. Exactly which spell they can cast depends on the kind of phage but is usually physically defensive to compensate for their vulnerability against physical harm. Despite appearances, all phage crystals are actually the same base substance.

Crysophage
''A type of insect with a long tail, the end of which is a huge, magical crystal. The crystal seems to make the creature invulnerable to magic.''

A particularly weak light-elemental variant of phage from Goznor. This phage has the ability to cast Shield.

Obsidian Phage
Phages that like dark, miserable places, where they lurk, waiting to feed on the misery and pain of all who enter their territory.

A which resides in Belfan's Elemental Temple of Darkness, with the appropriate element. It's slightly less weak to aether than other phages, likely an adaptation to living in haunted areas.

Amberystal
''A type of phage insect that is most at home in scorching hot places. It uses the focus crystal on its tail to cast fire spells like a mage.''

A fire-elemental phage from the outside of Xantusia. This phage is distinctive for having offensive magical capabilities.

Phage
The magical crystal on the end of this insectoid monsters [sic] tail possesses potent magic - which nullifies the effect of spells entirely - and is often used as a reagent in magical spell-forging.

Not a generic phage, but an earth-elemental one from the Lifewood. This kind has no weakness to fig and only partial resistance to aether. This is probably coincidental to its proximity to the Dreamwood, since they don't appear there. More likely, these advantages come from the vibrant influence of Belfan's Earth Crystal, allowing it to have a more complex nervous system like other insects of that region. It's possible that they're "generically named" for being the original kind of phage, from which the others evolved and cut down on the non-magical aspects of their metabolism when settling in caves and temples.