I would say black templars
LRC spam(probably the only
BT build that doesnt completely suck)
1.) Serpents can't hurt
LRC'S
2. They have objective secured, just like
WS' s
3) loads of assault cannon fire will roflstomp serpents
you can easily have 5 LRcrusaders in 1850 pts, but you will have around 30 models, meaning most other serious builds will take a dump on it. If you wanna list tailor, it will give eldar tough time, but (many) other things will destroy you...
Them pointy eared cheesemongering bastards....