Elder Evils

his essence transformed the serpent into a new physicality
that took on the madness of his previous demonic
form. Yet he retained serpentine features—partially as a
disguise if agents of the Queen encounter him. Sertrous
watched from his fen as the mortal races grew civilized,
established their own empires, and raised temples to
honor the gods. Sertrous grew jealous of their prosperity
and coveted the devotion mortals heaped upon the
gods. And so he waged war on them, plaguing these first
nations with armies of serpents and monsters from the
fen. (DC 40)
When the beleaguered mortals called upon one of their
deity’s most powerful minions, the solar Avamerin, Sertrous
claimed his first and greatest victory. Avamerin led
a great army into the fen to destroy Sertrous. The obyrith’s
minions were evenly matched with the angel’s, and in the
end only the obyrith and the angel survived to face one
another. The battle was intense, but in the end the solar
defeated the serpent. As Avamerin raised his sword and
prepared to strike the killing blow, Sertrous asked him a
simple question: “Why serve your lord when his playthings
can gain the same strength of power through their own
will?” Avamerin struck then, slaying Sertrous. He returned
to civilization with the obyrith’s head as proof of his triumph
and spoke to the nation’s priests of the demon’s foolish
words. (DC 45)
Yet in spreading these words, Avamerin unwittingly
released a great secret. Scholars and priests puzzled over
Sertrous’s dying words and made an incredible discovery:
One need not worship a god to gain the power of divine
magic. Rather than worship a god, a cleric could worship
an ideal and gain the same reward. He could worship the
mountains, or the sky, or the act of war, or himself. He
could even worship a slain obyrith lord. Avamerin saw
this plague of godless priests thrive and was powerless to
stop it. The solar realized his error, and when he confessed
to his lord, he was stripped of his rank and reduced to a
planetar’s status.
Enraged, Avamerin cast aside his servitude and stole
Sertrous’s head, claiming that the dead demon was wiser
than the gods. The gods recoiled and took from Avamerin
his beauty. If he would ascribe such value to a serpent’s
words, he would be one with them. The gods gave him the
visage of a snake and banished him from heaven. Yet the
damage had been done. The angel became the first heretic,
and he devoted the rest of his existence to serving the one
who had opened his eyes. In time, the devotion of Avamerin
and those he recruited to his Vanguard would be enough
to restore Sertrous to life and prove what the fallen angel
had come to believe was the truth beyond the lies of faith.
(DC 50)
GOALS
The Vanguard of Sertrous is an ancient organization of
murderers and raiders that has risen and fallen over the millennia.
Thousands of years ago, these nihilistic yuan-ti, whose
priests taught that worship of the gods was unnecessary to
gain divine power, surged from a trackless fen to lay siege
to the surrounding nations. The Vanguard was defeated, but
its teachings proved immortal. Every few hundred years, a
new zealot takes up the cause and leads a new army on the
march. (Knowledge [history] DC 30)
Although the armies through the years rose from different
regions, they all shared similar tactics and compositions.
Without variation, the Vanguard is led by yuan-ti but filled
with enslaved or dominated minions. When its numbers
reach the right point, its leaders unleash hordes of transformed
and corrupted slaves and minions in a wave of murder
and mayhem. (DC 35)
Although the leaders of the Vanguard claim to follow the
teachings of an obscure demon lord named Sertrous, the
Prince of Heretics has remained dead since he was defeated
long ago. The rank-and-file soldier in the Vanguard does
not know this. The teachings of Sertrous come to the leaders
through the decapitated head of their demonic patron,
preserved in a secret reliquary. (DC 40)
The first Vanguard army was led by Sertrous himself,
who marched upon his neighbors in a rage fueled by
jealousy. He coveted their cities, their accomplishments,
and most of all the adoration the citizens heaped upon the
gods. Sertrous wanted to be worshiped and held in awe,
and the only way he could accomplish this was through
conquest. He was slain by the angel Avamerin, who, it is
rumored, later fell victim to the Vanguard and was himself
slain. (DC 45)
Sertrous’s true reasons for waging war on the Material
Plane are more than mere jealousy. He wishes to return
to the Abyss and reclaim his realm now that the time of
the Queen of Chaos is past. Although he is dead, his spirit
persists both in his severed head and in the rebellious will
of Avamerin, who serves as the leader of the Vanguard in
Sertrous’s absence. With each war, the souls of those who
die in the Vanguard’s service are drawn into the Abyss to
await their master’s return, while at the same time the armies
and resources of his Material Plane enemies are depleted.
When his army of slithering petitioners in the Abyss is great
enough, he shall return to life and reclaim his throne as a
demon lord. (DC 50)
SERTROUS
IN THE CAMPAIGN
Avamerin remains hidden, a shadow leader of the Vanguard.
When one army is defeated, he waits for a few centuries
to start again, choosing a new champion to woo followers
away from the yuan-ti gods and to lead an army against
the world. As a result, the latest Vanguard can come from
anywhere in the campaign world where the yuan-ti are
active. The Serpent Reliquary itself, where Avamerin dwells
and Sertrous’s head is kept, exists in its own dimension
accessed by a portal placed in a remote location in the
campaign world.
TIMELINE
The following timeline is intended to help you construct a
campaign and provide suggestions for how the PCs might
meet the Vanguard and take part in the latest (and possibly
final) Serpent War.
EL 2: A merchant inherits an abandoned priory at the
edge of a marsh, but after he and his servants move into the
place, he cuts contact with his business partners. The PCs
CHAPTER 8
SERTROUS
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