Soultions

Problem 1) The Cait: The Cait needs to be chased, contained.  Some research can reveal that there are some things to which the Cait is particularly weak:

	-Nth Metal can be a bane to the Sidhe
	-Atlanteans may have, in the past, dealt either with the Cait or with similar Unseelie pests and developed artefacts to weaken it or trap it. One such artefact could still be known, but may be stored in a dangerous location, (idea: a set of magical weapons or gauntlets that can allow the lower-powered heroes who focus on hand-to-hand to have a significant effect on the Cait in combat)
	-The Sidhe are said to be weak to iron. Consecrated iron, such as a holy sword, is an excellent weapon to hunt down and incapacitate an Unseelie.
	-The Unseelie bristle in the presence of demonic energies and entities. While not particularly weak to them, they cannot resist the urge to confront them and humiliate them. Demonic artifacts are irresistible to the Unseelie, as they will seek to either own them or destroy them in contempt, making them excellent bait.
	-Magical artefacts of order or white magic repel the Cait if they are sufficiently strong. Several may be used, therefore, to 'chase' the cait and drive him towards an ambush. The cait cannot teleport when in the presence of these objects.


Problem 2) The souls: Keith and the Cait need to be reunited and merged.

Mystical research will reveal that soul-merging is considered a disreputable ritual and, as such, is generally frowned upon.  Some of the things that will pop up are already known, namely that upon merging the soul with lesser power will become dependant upon the one with the greater power for its existence. This is a problem that arose with many early soul-merging rituals and, like Keith and the Cait, some were separated by powerful magics only to result in the fading out of one of the parties. The older ritual focused on the use of a mirror-like blade to slaw both targets, one after the other, and thus merge the soul of the first with the soul and body of the other. The results, although effective, were unstable, with partially-merged souls.

A more refined ritual was allegedly created by Gwydion of the British Isles. Instead of relying on mirror blades, Gwydion heeded the advice of the Raven King of Faerie and instead modified the ritual to include two glass swords called Brightkillers. The Brightkillers are creations of Faerie and may only be found in their forge at the Chapel Perilous under the hills of the sleeping queen. These blades are legendary due to the powerful soul-piercing enchantment laid upon them. The swords were created to fight the Faerie Chimaera, mythical beings that were soul-amalgam of several souls, and thus the Brightkillers were capable of dividing these souls into their individual components, diminishing the threat.

Although the forging of the glass words was considered the exclusive secret of the sleeping queen, the Circle Oroboros, over millennia, was able to acquire the secret, though not without significant loss to its ranks when the Seelie court found out.
Our heroes, however, will have to brave Faerie and the sleeping queen's hills to retrieve the swords. Only two swords may be retrieved from the Chapel Perilous at one time, only one sword per person, and only someone with great love or purity of heart may enter the Chapel unharmed. The sleeping queen has been gone for thousands of years and the area surrounding the Chapel has been overrun by creatures from the Unseelie court, yet the Chapel retains its purity.
The ritual itself requires the use of the two swords:
	-One sword must stab the first target (the Cait) through the heart and thus absorb its soul into the blade.
	-Then, both blades must be thrust into the second target's chest (Keith's) simultaneously. The second blade will draw Keith's soul out into itself, and both blades present in the body at the same time will shatter, acting as catalysts for a perfect fusion.
The fusion will be far more refined than the primitive mirror blade ritual and create a seamless unity, one that will not be susceptible to separation again.

The Cait has a collar of thorns around his neck, it is the Circle's doing- a spell that exacerbates his nature. During his time communing with Keith's soul, he has picked up some human notions and sensibilities. The Circle placed a spell on it to keep the Cait from considering honoring his promise to Gar. The collar keeps the Cait focused in the moment, and on its chaotic nature.  For as long as it is on, it will also prevent the soul merge from ocurring- the collar, however, is easily dispatched - it just needs to be destroyed with an artefact made of cold iron.