I would think multipule strength 8 barbed strangler templates would do a good job for them
Thus negating their Feel No Pain and if the suits take a wound they die to instant death, my spider senses tell me though he would just place them all on his 2+ save suits and pass most of his saves :p
As for mehreens yeah he will prolly blow up your land raider with all the melta-weaponry+ his hammerhead so gating praying and then assaulting would be teh best option. I don't what defense he has against the Dirty Lash of Slaanesh, Turn 2 assaulting Orks and the new durtwolves though.
Should be interesting to see the results.
Thanks,
Lee
