"Clee-San" Deep Space Research Frigate

Info Here.
(take this with a grain of salt; it's not official)

In the final days of their control over the Mothership's PDA, Kiith Somtaaw triumphantly built one final ship, the Clee San, a top-of-the-line deep space research frigate. Students of history will note that the names of all three vessels derive from the names of temples along the old Shimmering Path: Kuun-Lan, "Purifying Flame", Fal-Corum, "Silent Wayfarer", and Clee San, "Truth Seeker"

"Ecclesiam is the Clee san in a very, very old story itteration."  - Chris Stewart, Barking Dog

This vessel so far has been seen only in cinematic cutscenes, so it probably is a story-oriented vessel in the single-player game only (like Elson's destroyer in Homeworld), and not available in multiplayer games. One of the mission objectives of the early missions is to "Find CLEE-SAN." It would seem to be somehow related to the discovery of the Beast and the initial infection of the Kuun-lan.

Pics Here.
(click to view the source image)

Infected Command Ship

An animatic cut-scene of the Clee-San