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 one interpretation, they are gifts from the divine Lustlord to his chosen. Another version claims that they are fragments of the Lustlord's shattered being, finding a strange consistency with the teachings of the Church of Ivala. Riala can only confirm that a shard "really is a piece of a soul, or at least similar to one. Whose, I couldn't tell you."

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 suitable shard recipient, though all known Incubus Kings encountered so far have been male, with only a single exception. Riala says that she couldn't use the shard that she found, though she didn't explain explicitly why. This may mean that shards (usually) don't accept female recipients, or only that Riala thought so, and/or she didn't know how to make the necessary adjustments. Another possibility is that merging with the shard would immediately attract the attention of her master, with fatal consequences.

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.

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.

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 (rules Philon, duh)
 * 3) The Empress of the Orgasmic Empire (another obvious one)
 * 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.

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