The Firstborn of Illuvatar
This is a thematic fellowship representing the joined forces of the Eldar.
The Caliquendi are the "Elves of the Light" or those clans of the Eldar that after awakening in Middle Earth, followed the call of the Valar all the way to the undying lands and beheld the Light of Valinor. These were the Vanyar, Noldor, and the Teleri. Amongst these clans, only the Noldor returned to Middle Earth in service to the terrible Oath of Feanor to reclaim the silmarils...and are represented in game by the Noldor trait.
The Moriquendi, or "Elves of the Dark", are the various clans and kindreds that never made it all the way to Aman, but rather fell aside and sundered themselves along the way and chose instead to dwell under the starlit darkness of Middle Earth. These were the elves of the East (some of whom may have been captured by Morgoth and transformed into orcs and goblins according to legend), the Silvan or Wood elves that settled in Mirkwood and Lorien, the Green elves dwelled in Ossiriand on the western slopes of the blue mountains, and the Sindarin or Grey elves who made it all the way to Beleriand and never embarked across the sea. These would include Celeborn and Legolas. All of these groups collectively fall under the Silvan trait for game purposes.
The Noldor quest and engage/defend enemies and do Noldor things (discard cards as a power up resource). The Silvan supplement questing while killing all enemies engaged with themselves and the Noldor deck through ranged attacks and direct damage, and also do Silvan things (enter/exit from play). These decks have been very successful and have taken me all the way through the Grey Havens up to the Drowned Ruins of the Dreamchaser Cycle, as well as the Voice of Isengard and the entire Ringmaker cycle. So far, they have beaten every quest readily except for the Dunland Trap... and that one only lost by losing a hero in the final attack of the final stage. The Dunland Trap is pretty tough for decks not specifically built, so it's safe to say that these decks are effective without compromising theme.
For tactical discussion of each deck, please see individual deck descriptions.