I'm thinking a farseer with doom and Runes of warding, with 5+ pathfinders is a nice little allied contingent, maybe with a Fire Prism or some Fire dragons in a waveserpent. Have yet to play Eldar in 6th though and my choice of units is a bit limited.
40K - Dark Angels, Dark Eldar, Necrons; Lord of the Rings - lots; Bloodbowl - Dwarves, Wood Elves; SAGA - Anglo Danes & Welsh; Guildball - Morticians, Engineers; Dropzone/fleet - Shaltari