Soul shards

Incubus Kings derive their power from "soul shards" or "fragments", which meld with their souls, giving them their powers of lust and corruption. The existence of the shards is little known outside of the lands dominated by the Kings, and even among those in the know the exact nature of the fragments remains a mystery.

According to religions, they are related with the divine Lustlord. While the teachings of the Church of Ivala, claim that they are fragments of the Lustlord's shattered being, the church of Lustlord views them as His gift to his chosen. Xerces has confirmed that the shards were once a unified Shard in the possession of a being that was considered as the Lustlord. However, what caused the death of the Shard Holder and the fragmentation of the Shard remains a mystery.

Life cycle of a shard
On their own, the soul fragments seem to be passive, existing as pieces of magic essence that can somehow be taken and carried around. To activate, a fragment needs to be implanted into someone's soul, thus granting the receiver powers of the same nature, if not always the same magnitude, as the ones of an Incubus King. Apparently, the process doesn't even have to be voluntary - Riala implants a soul shard into Simon without him noticing.

It's unclear if there are any strict requirements that make someone a suitable shard recipient. Being male seems to be generally considered a requirement althogh the succubus Esthera found a way around this (by walking various paths of power inside the Tower, allowing her to bend it to her will). Riala says that she couldn't use the shard that she found, though she didn't explain explicitly why. This may mean that shards don't normally accept female recipients, and she didn't know how to make the necessary adjustments.

Though shards seem to grant their recipients a practically eternal life, Incubus Kings can still die (read: be killed), and the shard appears to persist after their death, once again reverting to a passive state. It's implied that Incubus Kings increase their power by killing and absorbing the fragments of other Incubus Kings, thus putting at risk everyone hosting a fragment who doesn't have an army behind their back. Also, according to Xerces, an Incubus can become mortal again, though it is not specified if there is a way to abandon the shard safely or suppress its rejuvinating effects.

If a shard is destroyed, the energy slowly reforms elsewhere in the world.

One thing to note about the shards is that they conflict. Aside from their holders' usual inclination to kill each other off and consolidate power, if two shard-bearers physically touch then their shards will magically clash in a direct power struggle. For unknown reasons, Simon was able to temporarily suppress his power and this effect when hiding his nature from Esthera, but this is implied to be very unusual. It may be related to Simon refusing to embrace his power and slowly converting the shard to be more compatible with his will. The clashing effect returned later in Simon's stay in the Orgasmic Empire, when he began actively developing his powers under Esthera's guidance, and can be seen in the Nalili Double Team sex scene.

Effects of a shard
Once a soul shard is absorbed into a host, they gain many abilities, but those abilities come with a price.

An Incubus King requires regular sex or they will die. Simon experiences this after his escape in the Prologue, and only loses the deterioration after having sex with Aka. Riala implies that if an Incubus King doesn't have enough willpower they will lose themselves to the need and mindlessly seek out partners, but notes that Simon probably has the willpower to resist until he dies.

Additionally, soul shards attempt to reshape their bearer's minds to be less controlled and selfish, and those who can't or don't want to resist abusing the powers have similar personality traits. More unsettlingly when a soul shard from a previous Incubus King is absorbed after their death there seems to be a bleed-over of personality and mind to the new bearer. Presumably this is why The Incubus King was so scattered and why he couldn't even remember his name, he had absorbed too many shards in his lifetime. As such, he was literally not the same person he was when he originally absorbed his shard, but rather an amalgation of scattered minds and desires.

Known fragments
Fragments vary in "size" and major fragments give their hosts more power than the lesser ones. The latter shouldn't be underestimated, though, because there are more of them and they can be more easily hidden or overlooked, no matter if they are fused with someone or not.

Major fragments
While every fragment has the potential to turn their host into an Incubus King, only seven actually claim such power at the time of the Gathering. In order of seniority, they are:
 * 1) The Lustlord (rules Rodak)
 * 2) The Anak of Philon
 * 3) The Empress of the Orgasmic Empire
 * 4) The Incubus King (a big chunk of Arclent)
 * 5) The Lord of Blood (a Roaming Fortress)
 * 6) The Fucklord (Erosia)
 * 7) Skullcrusher (something in the Renthnor Wilds)

Before the Gathering, Riala mentions that there are five fragments comparable in power to that of the Incubus King, including his own, and all of them "are held by world powers", including Erosia. Since neither the Lord of Blood, nor the Skullcrusher rule any nations, it's easy to guess the owners of the major shards with a high probability.

After the Skullcrusher's (un)timely demise, his fragment was apparently taken, and perhaps destroyed, by his slayer.

Minor fragments
The host of a small fragment can absorb other fragments to gain more power, but this also increases the likelihood of being detected and eliminated by the host a major fragment. So far, the whereabouts of only two minor fragments are known:


 * Simon's fragment;
 * A small fragment forged into an ancient Incubus King's suit of armor that the party finds in the Dark Ruin.
 * Stineford Incubus King
 * Erosian Orc Fucklord Incubus King

Other fragments

 * One fragment in the possession of Wendis. Though due to how it was changed upon being absorbed she doesn't have the powers of an Incubus King, though she can still manipulate sexual energy.

Power caches
Occasionally, the party will encounter caches of "power" or "corruption" that can be absorbed by Simon. Those should not be confused with minor soul fragments, as confirmed by the author:

Many of these caches were created by The Incubus King to replenish his power if needed, but Simon, as a shard holder, can use them as well.

Divine shards
At the end of the Third Arclent War, Riala reveals that another kind of shard exists: divine shards. Not much is known about them. They seem to be the counterpart of incubus shards, and to target women instead of men. Simon's harem is able to use one to rejuvenate themselves. It's commonly speculated by the characters that these shards are the origin of the Goddesses' powers.