I knew losing a game against you would be good for something
Fought it several times, it's the Eldrad for Tyranids. But since my main army is Necrons I never seem to have much trouble against it. But I do know that thing can be a nightmare against low LD armies.
I also once did something that was frowned upon namely I charged Eldar into the doom and put the rest of my forces 6 inch away. Having a reroll 3 Save and Ld10 Meant the doom wasn't getting any wounds build up. A Wraith Lord later killed the darn beast. ^^;
You know you only get Cover (For some reasons.) Or Invun, right? No armour saves are allowed.
Dark Space Elves
Titans & Knights
Ye Olde WMS