To kill a god...

[Reclusiarch Darius]

The Eversor is a fantastic weapon against Necrons. I've had mine wipe out entire squads by himself, its a beautiful thing to watch :) he usually dies to massed gauss after emerging from combat, but it's still highly amusing to watch him come in from Outflank and do his thing.

 

Another great unit is a fire support Lord. The plasma cannon servitor is great for splattering Sarabs (double wounds because it's a blast, ID's whole bases) and softening up Warrior squads (4-5 less Warriors means bigger win for the PAGK when they charge them), the heavy bolter+psycannon chips away at Warriors and helps in countering things like Destroyers and Wraiths (by forcing heaps of armour saves and out-ranging their shooting/assault), and the Mystics keep your lines safe from 'Veil' shenanigans (oh yeah, I see you landed there with a 'Veil' teleport. Now I'm resolving a plasma cannon and 9 x S5/6 shots on you).

 

PAGK should be 10-strong, incinerators are personal preference (more wounds = more saves = more dead Necrons, but between 3+ armour and WBB incinerators aren't that good). Slam them into his Warrior squads, watch them disappear (with the Eversor there is an outside chance their return attacks might slap him down, with PAGK the Warriors don't have a hope). He'll be crying into his beer all game, because of his lack of AP3 (the Lord, Heavy Destroyers and Monolith are the only things that can punch through power armour). Landraiders for delivery, Crusaders being a good choice as lascannons are largely useless (can snipe Destroyers but they're not going to hurt the Monolith) and you'll need the frag bonus if he's hiding out in cover (which he probably will, to prevent an early Phase Out).