A friend of mine I Wargame with owns Nagash. He is very annoying to fight as the way my friend plays him makes him almost impossible to kill. He uses a Legions of Nagash battalion called the First Cohort which lets his Harbingers/Archai absorb damage for Nagash on a 4+ when nearby. Essentially giving him a 3+4+6+ with 28 wounds...not to mention his 40 skeleton block. Please nerf LoN GW. Anyways, I can't seem to find a way to take this guy down and he's not really avoidable either.
Use high rend high damage units. Ignoring him is also viable. Grand host of Nagash, with Nagash present, has a very small board presence. Death also moves pretty slowly. Just out play him on the board if you can't kill him.
Oh that's actually my bad, I put them in the wrong order. Although that does make me wonder. He would still get his 6+ deathless minions right?
He definitely gets deathless minions. This is the errat text related to his battalion. Page 90 – The First Cohort, Ceaseless Vigil Change to: ‘Before you allocate a wound or mortal wound to Nagash, you can pick a friendly Morghast unit from this battalion within 3" of Nagash and roll a dice. On a 3+ the wound or mortal wound is allocated to that unit instead.’ He doesn't get to filter the damage through his Nagash save first.
Okay thought so, is there anything the Seraphon have that could do solid damage to him? A great remember double Bastiladon drop with Master of Star Rituals and is the best I've come up with.
You can try to Spam Engine of the Gods & D6 mortal wound him off the table. Salamanders are decent killy with -2 rend and D6 damage. Also, running a Rippderdcatyle heavy Shadowstrike Starhost should do the trick. A Scar Veteran on Carnosaur with the Artifact Sword of Judgement on his spear is terrifying. With enough Razordon and Bastiladon fire you should be able to kill off his escort of Morghast and then deal with Nagash the following turn.