1d4 Random Altars Of The Illusionist Kings Encounter Tables For Your Old School Campaigns

Before the oceans drank Atlantis there were rulers who built kingdoms from the stuff of dreams and conquered by the power of nightmares. Reality ran like wax under their gaze & the very world sang with their songs of pseudo matter made flesh. They conquered nations with armies of shadows and pulled their power from the collective power of the dreams of humanity themselves. They were the blessed of the Trickster gods and their power was such that even today if one looks their markers still exist. But adventurers should beware for even though reality rebelled against these twisted tyrants of tricks and illusion; their power still sleeps in their relics. When one finds their works their power echoes throughout eternity.
1d4 Random Altars Of The Illusionist Kings Encounter Tables

1. The altar of A'phaugugyi - Those disturbing this altar will have to save vs wands or be subject to having their greatest nightmare made flesh as a three hit point monster made of echoing magickal energies. The effects will be the same as facing down a phantasmal force monster and the thing will try to murder their target to take over the corpse in a mockery of life and it will have an undead's unholy hunger for flesh. The altar rattles with the power of its namesake and from time to time it will project illusions of treasures, jewels and the like to lure in adventurers Each new moon the altar will create a free will monster duplicate to go and cause mayhem in the world. 
2. Thazotlhano's legacy - This altar has thousands of whirls and star like patterns across it, these will come to life at the whim the guardian spirit. The whirls and illusion that this altar creates will try to charm any target. The altar will summon a phantasmal possessing spirit to take over the body of victims as it creates a pseudo reality in order to seduce & beguile the targets in order make possession far easier. Those taken over will experience a whole gamut of emotions and trials as they become passengers with their own bodies. Their spirits are suppressed as the altar weaves and takes the person over completely. '
3. Egolothothac's Binding - This stone has many facets in various planes of existence at once. Those stepping around it will wander into another reality or dimension. The altar will project pride and false feelings of achievement onto its target even as it planarly shifts them into another. There are demons of illusion who wish to use the fools attracted to other dimensional  temple of the shadow illusions of the area. Those who can should beware even as 1d4 critters from HP Lovecraft's dreamlands cross over into the reality of the altar. 
4. Ibbotho-otha's Stepping Stone - This altar bares resemblance to the ancient stages of the temples of the illusionist kings. This stone is used to summon the demon Ibbotho-otha who has been locked away in the underworld of the dreamlands and yearns to be back among the living to spread darkness of his reality bending powers. This demon thing will grant 1d4 illusions of Ibbotho-otha and should the owner use these spells the barrier around the demon god will begin to weaken the fabric of the local space time in order to free the dark ones.