Tranquility's End
Long ago, an autumn eladrin who's name has been long forgotten travelled from the feywild to the small community of Tranquility. He and his entourage of disguised centaur and satyr were sent by their Archfey patron to help rid the villagers of a terrible monstrosity that had befallen their lands, feasting on their livestock, spoiling their crops and picking off their farmers. The Archfey's ulterior agenda to bolster their own followers went according to plan after his emissaries slew the creature plaguing Tranquility, whose citizens fell in love with the charming hero and his patron in turn.

All seemed like a fairytale ending, till the jealousy of the town's mayor, Eli van Hassen, had the eladrin and his entourage framed for heinous crimes against the mayor's daughter. The townsfolk quickly turned from adoring fans to angry mob and somehow subdued the fey, murdering the entourage where they fled and executing the eladrin by public beheading in the middle of the crossroads of the mayors estate. The mob dumped his body off the nearby bridge and into the running water below, his body coming to rest under a yellow maple tree on gentle curve in the river. The Archfey patron had already sworn vengeance against all involved and their families for generations to come, before the eladrin's head had even come to a stop under a nearby rosebush.

The next morning, van Hassen, his daughter Tahlitha and many of the townsfolk present at the killings woke up in a land that was a grotesquely beautiful reflection of the surrounds they knew. But that wasn't all. The moment the lost citizens ventured out of their homes and onto the feywild reflections of their own streets, they were greeted by the rolling peel of approaching hooves, like distant thunder before the storm. Those who stayed outside were quickly confronted with the eladrin risen again, headless and seeking revenge. He decapitated his murderers one by, testing to see if their head can fit his own, finally hunting down the mayor at his fey reflection manor. However, the gates of the van Hassen estate mysteriously kept him at bay. To this day, he waits till the mayor and his people leave the grounds to take his final head.

The Horseman and his entourage are forces of nature of the Endless Road. They appear almost anywhere, at any time, and demonstrates no motivation other than slaughter,  the search for his own head and exacting revenge on all linked to his murder; those who stumble through the bleed between the feywild and the material plane and those in still in Tranquility. None are innocent as per the curse of the Endless Road.

The Endless Road
To the average adventurer he appears seemingly at random, when in actual fact he can sense anyone travelling the Endless Road and chooses his quarry precisely. Sometimes he attacks instantly; at other times he harries foes for hours, letting them escape so that he might ride them down once more. He most frequently appears where the road is wide, or where numerous paths converge, allowing him a wide field of battle. Those who try to flee the Endless Road are either run down by the Horseman or find themselves on a never ending, featureless highway, lined with dense forest and repeating the same twists, turns and straights until they perish, go mad or turn back.

The Horseman’s arrival is heralded by a sudden clouding of the sky, a moaning wind, a swirling of autumnal leaves and a damp, rising mist until little of the world beyond the road is visible. Day or night, the light that shines through the clouds takes on the sickly blue of the moon.

The Horseman appears amid thundering hooves atop a stead the locals have dubbed Spitfire. A headless apparition in red jacket with gold embellishments, white soldier's uniform and weather torn cloak fanned out behind riding a stead of spitting flames. He stands in a saddle of blackest leather, and holds aloft a blood-stained axe, it's unimaginably sharp edge gleaming in the moonlight above and flames from below.

Bound to the Road.
The Headless Horseman is a force of nature, a wave of slaughter crashing along the the winding Endless Road and any thoroughfare that branches from it. He can sense and track any being on the road, specifically knowing and hunting those directly linked by family, patronage or favour to his murderers.

However, he is solely bound to the road itself, unable leave it by any means. Riding his Nightmare companion, he can fly from the ground, but the force holding the Horseman at bay is still present above ground level.

Additionally, any creature within 100 feet of the Headless Horseman also becomes bound to the road. When a creature tries to flee from the Horseman through the thick tangle of feywild trees, they emerge back onto the road on the opposite tree line at the end of their movement, regardless of the distance they chose to move.

Finally, the Headless Horseman cannot cross any body of water he himself could not jump (20 feet with a running start or 10 feet from stationary), even on the back of Spitfire. Therefore, the wooden roofed bridge at either "end" of the mapped, "known" area of The Endless Road becomes a barrier the Headless Horseman cannot cross. He can enter the bridge above the flowing river below, but he cannot step foot on the other side of the bank.

Curse of the Horseman.
Any who have ties to the van Hassens or those who executed the Headless Horseman are marked for revenge for generations to come. Their descendants in either the Feywild or the Material Plane become the Headless Horseman's quarry. In the Material Plane, those who enter the derelict van Hassen estate, even accidentally and in the Feywild, any who strike a deal with, do or owe a favour to, take refuge from Eli van Hassen or his employ become the Horseman's quarry also. The Headless Horseman comes for his quarry's heads either the following dusk, the moment they step foot on the Endless Road or at dusk on the birthday where they turn the same age as their descendant. 

Additionally, Tranquility and The Endless Road will not be rid of the curse of The Headless Horseman till he takes the head of Eli van Hassen or his own head is reunited with with his own body. If the Headless Horseman dies, his body slowly crumbles into a cloud of orange embers, red rose petals and yellow maple leaves, like charred remains drifting away on a breeze. He then rises again the next dawn at the site of his grave on the plane of existence he last died.

The Endless Road seems literally to have no end. While some travellers find themselves eventually returned to paths in the real world, or other regions of the Autumn Court, most who trod the Endless Road never reach any destination at all. They may walk until all traces of inhabitation are lost behind them, and still find nothing but woods or hills to either side, and the highway stretching—always stretching—before them.

Lair Actions

On initiative count 20 (losing initiative ties), the Headless Horseman takes a lair action to cause one of the following effects; the Headless Horseman can’t use the same effect two rounds in a row:

• A strong gale crashes down the Endless Road at the Horseman's back as though he had cast the gust of wind spell, but as wide as the current stretch of road. The wind lasts until the initiative count of 20 on the next round.
• The Headless Horseman casts create bonfire on three seperate locations within the spell's range.
• A natural fog rolls in from the tree line as though the fog cloud spell had been cast. The fog lasts until initiative count 20 on

  the next round.

Regional Effects

The Endless Road spans across the Material Plane and the Feywild, crossing over at the wood roofed bridge at "either end" of the Endless Road itself and outside the sleepy village of Tranquility. In both planes, this is the location where the Headless Horseman's body came to rest after being dumped in the river. The known and mapped stretch of road between the two bridges is dead in the forests of the Autumn Court in the Feywild, unbeknownst to the inhabitants. It is a reflection of the small stretch of road in the Material Plane around the small town of Tranquility and the long abandoned van Hassen estate. In the 150 miles around the area in both planes, one or more of the following effects:

• The Headless Horseman is aware of any creature on the road.
• The area is in a perpetual state of autumn; the trees are in autumnal colour, the sky is often cloudy and usually only parts when the moon is at its zenthin, a light mist covers the ground at night and a cold breeze is often blowing through the forest.
• Wild pumpkin grow virulently, with the pumpkins growing large and naturally with Jack'o'Lantern smiles in the Feywild.

If the Headless Horseman beheads Eli van Hassen or his own head is reunited with his body, these effects fade over the course of 1d12 days.