Xag-Ya and Xeg-Yi

Life turns up everywhere, even in the raw energy planes. Out of the blazing, explosive vitality of the Positive Energy Plane came the xag-ya; from the cold, devouring void of the Negative Energy Plane came the xeg-yi. Somehow minds took shape there and built bodies from the surrounding force.

Some scholars doubt either is truly native. A plane of pure life seems an unlikely place for something individual enough to think and move, and a living creature made of anti-life sounds like a contradiction. They suggest the pair formed in isolated pockets of energy somewhere else, or were made by an unknown power for its own ends. Nobody really knows, but the two are so alike and yet so opposed that a shared origin seems likely.

Both are spheres of energy trailing many writhing, octopus-like tendrils. Apart from two narrow slits that suggest eyes, and hint at an alien intelligence, the globe is featureless. At a glance the only difference is color: the xag-ya is lustrous silver, the xeg-yi a dull, lightless black.

Both lash out with whiplike energy tendrils for 1d6+6 points of damage. A xag-ya's touch overloads living tissue with power and sets paper, cloth, wood and other nonliving combustibles alight. Every other round it can also fire a bolt with a 10-foot range that deals the same damage and ignites the same materials, and it heats metal white-hot for 1d4 rounds, scorching anyone touching it for 1d4 per round. Magical metal items save vs. electricity to resist.

A xeg-yi's touch drains life and corrodes, making paper, cloth and wood age and rot. Its bolt, also usable every other round at 10 feet, deals the same damage and decays even metal and stone, which must save vs. electricity or crumble into worthless ruin.

Only weapons of +1 or better harm either. Few spells affect them at all: xag-ya are vulnerable to cold spells and xeg-yi to magical fire, both can be struck by magic missile and disintegration, and neither can get past a shield spell. Away from home either can be banished by abjure, banishment, dismissal, holy word, limited wish, plane shift, wish or dispel magic (treating the magic's level as double the creature's Hit Dice). Nothing else works. A rod of absorption or wand of negation can block a xag-ya's attack, and a rod of cancellation or mace of disruption protects against a xeg-yi; neither creature can damage these four items.

A slain creature bursts in a 10-foot radius, dealing 2d6+12 points to everyone inside, who are also affected as if hit by its bolt, so items may need saves.

Each wanders alone, ignoring even its own kind. They are believed to be very intelligent but have no language or way to communicate. Curiosity drives them across the planes to watch and wander. They are not hostile, but their touch threatens almost everything, so others see them as dangers and fights follow often.

When a xag-ya and a xeg-yi notice each other, they rush together at once. On contact both are destroyed in an eruption dealing 4d6+24 points to every living thing within 30 feet, randomly heating or corroding objects in the area. Whether hatred or some deeper compulsion drives this, no one knows.

Both feed on energy of every kind. Since individuals never interact, they must reproduce asexually, though how remains a mystery.