Ok, so here's my attempt at a good 1,500 pt. Biel-Tan list
Children of the SwordwindAvatar of Khaine 155
Farseer Thalandir
-Spirit Stones
-Doom
-Fortune
-Mind War
-Runes of Witnessing
Total: 160
8 Striking Scorpions
-Exarch Zar'lonth
-Scorpions Claw
-Stalker
Total: 160
-Dedicated Wave Serpent
-Twin-linked Brightlances
-Spirit Stones
Total: 145
10 Dire Avengers
-Exarch Rhagan
-Twin Shuriken Catapults
-Bladestorm
Total: 152
10 Dire Avengers
-Exarch Exlarthan
-Twin Shuriken Catapults
-Bladestorm
Total: 152
10 Dire Avengers
-Exarch Helias
-Twin Shuriken Catapults
-Bladestorm
Total: 152
Ranger Squad "Unseen"
5 Rangers
-Pathfinders
Total: 120
Fire Prism "Zelogath"
-Holofields
Total: 150
Wraithlord "Garganthrone"
-Brightlance
-Eldar Missile Launcher
Total: 155
Ok, so here's the fluff behind it:
Farseer Truquar Elenzar Thalandir is a Farseer with a different sort of vision to the rest of those on Biel-Tan: he believes that the only way to attain peace and order throughout the galaxy will be by banding together all of the 'good' races in the galaxy. Many mock Thalandir's vision, but he is a powerful and exalted Farseer on Biel-Tan, and for that he has respect, respect enough that he has managed to assemble a particularly large band of followers who are willing to join him on his quest to fulfill this vision.
Thalandir has left Craftworld Biel-Tan to start his great crusade, and many, many Eldar have gone with him. The main militant Commanders of his forces are the Autarchs Ghar'lon and El'syra, who also happen to be the twin son and daughter of Thalandir. Through the use of Webway gates, Thalandir can regularly receive reinforcements from his followers on the Craftworld.
Tactics:
Obviously Thalandir will ride with the Scorpions in the wave serpent. Wraithlord Garganthrone will go tank-hunting, while the Avatar will lead the Fearless Avenger Squads. The Prism will lay down impressive amounts of fire on the enemy, and the Rangers deployment will depend on the situation.
The reason I took these units is because they are a mixture of Elite soldiers and powerful heavy units like the Avatar and Prism. I generally don't take many Guardian units as Thalandir needs elite and powerful units to fight with him, not citizens of the craftworld.
I have also posted a bit of an Eldar Litany here, check it out!Thanks in advance for comments and criticism etc.