Shadowmasters

The shadowmasters are a clan of humans whose home is a shadowy castle within the demiplane of Shadow and who cross to a prime world whenever they get the chance, hoping to rule it through their shapechanging. They control their flesh completely, reshaping any part of the body, and can take the form of any living creature, even some hideous nonhuman horror. Without magic, the only tell is a golden light glinting in their eyes; the DM should call for Wisdom or suitable proficiency checks, modified for the situation.

Their fluid bodies make them extremely tough. They regenerate 1 hit point per round, are immune to poison, and can be harmed only by silver or magical weapons. Silver always deals maximum damage, and those wounds do not regenerate. Their high Hit Dice and good Armor Class come from constant reshaping mid-fight, even sliding internal organs out of place, which makes a killing blow hard to land.

A shadowmaster can fight with weapons, and some are powerful members of player classes with unlimited advancement as humans, though only the clan's leader can cast gate or other planar magic. Others grow spiked tentacles or pseudopods, receiving attacks according to class and level, each striking for long sword damage (1d8/1d12).

The clan is ruled by the High Shadowmaster, usually its mightiest mage, and members constantly scheme against one another for rank and favor; they are so paranoid that many keep shifting shape just to be harder targets. Only the leader can open a way to the Prime, and most of the clan, which rarely tops 100 members, waits eagerly for a turn to go through, weaken the world's good forces, and prepare an invasion. Shadowmasters seem effectively immortal barring death in battle, yet they do appear to age, since a younger, stronger rival periodically topples the leader. Perhaps leadership or planar magic wears them down.

They cannot breed among themselves. Each new shadowmaster comes from a union with an ordinary human, and the infant is usually stolen soon after birth by its shadowmaster parent.

Their shapeshifting is not inborn. Something in the demiplane or in the castle grants the power to every human who goes there, and it fades soon after a visitor leaves. A newcomer must make a Constitution check each round until three successes in a row, gaining control over the random shifting.

Shadowmasters eat anything, but prefer living flesh, ideally human. They feed by sending out tentacles that end in fanged mouths, gripping the prey and often devouring it from inside by way of the mouth or other openings.

Every shadowmaster descends from one ancient mage, the first to break into that demiplane. Centuries ago they raided a famous wizard's home for magic, and an ancient sage-wizard killed one of them, earning their lasting hatred as 'the Enemy.' He set wards to warn him whenever one entered the world. Twice in recent years they have tripped those wards: once when a pair came hunting a young woman's newly awakened spellflame, and again during a year when the gods walked the world, when a large force tried to murder the sage and replace important people. Each time he, a famed adventuring company, and a trio of rangers armed with a silver sword from the goddess of magic hunted most of them down, even carrying the fight to the castle itself, but a few remain loose.