I recently proxied a battle between a "dread Saurian" and "Archaon" (both of which were in fact books) with my brother. He played Archaon, I was the 'saurian. I lost. We rematched. I lost on his first turn (dammit that slayer of Kings is scary). We rematched without the slayer of Kings ability. I lost. We rematched yet again (yeah, not much was happening in our house that weekend) I lost. I created some freakingly overpowered rules for dread Saurian ( and also fixed his magic phase: I mean come on, a 'saurian at 11+? Not fair. See the rules below) I lost. Archaon is truly the most fearsome lord around. Then Nagash stepped in (thanks to my other brother) and beat Archaon into a pulp. Cheers Dan! What im getting at here is Archaon is stupidly overpowered. But I guess you already knew that. If you play someone who brings Archaon to a battle, just summon as many carnosaurs and Dread Saurians as you can. Do not let him near your main army. Send the best troops you have at him and roll well.
I've killed Archaon a few times, I think it's very fortunate that he's got the Daemon keyword and we get huge bonuses against Daemons.
So Nagash can beat Archaon to a pulp without much trouble pretty much every time? Damn I really want to watch that happen...
Not at all, in the matches between Archaon and Nagash that we've done either Archaon annihilates Nagash, Archaon just regularly beats Nagash, or Nagash beats Archaon but is left on 1-3 Wounds by the fight. Archaon dominates most fights from my experience.
Between the chance to dispel, the 50% chance of it missing, and Archaon ignoring the affect of all hostile spells on a 4+, Hand of Dust is not that threatening.
The last ability before it goes on to the Magic section, his The Everchosen ability. Any time he's affected by a hostile spell in any way, he ignores it. This includes scenarios such as if he attacks a unit that has Starlight active because their Starlight gives any attacker a -1 To Hit, meaning he's affected by the spell.