Over at the Bad Dice Podcast, Ben has listed his top five DP builds. The first four do not scare me very much - I have enough units to withstand a breath weapon and usually plenty of high strength attacks to deal with two T5 monsters. However, Ben's top one is scaring me.
Mark of Nurgle
While the Lore of Nurgle is fairly easy to deal with as a tough Orc, Lore of Death is not, and this guy can choose either. He is also flying into a combat of his choosing where there is not a single thing in my army that will hit him on better than 6+. I would never fight him with a character, not even on a Wyvern, and my usual monster-hunting Black Orcs will not be able to deal with him on their own. There are three, possibly four things that I would bring if I'm confident that I'll go up against a Nurgle Prince.
With enough artillery or enough luck, your Rock Lobbers can score a direct hit on the Prince, and the Doom Diver is a dangerous threat when wounding on 4+. Dual Doom Divers should be mandatory when going up against the WoC anyway, so this can be doable as well. If you can't kill the Prince, you have to trust in close combat.
These guys are already a standard option when going up against the WoC due to their ability to ignore armor saves. Against the Prince, however, it's not so much that ability but the fact that puking means an auto-hit that attracts me to them. 6 Trolls will be able to get into close combat with the Prince and at T5, the Trolls should be wounding him about three times each combat, so the Prince should go down in 2-3 rounds. Even though he has a flaming breath weapon, that does not concern very much, since he is unable to follow that up with a Thunderstomp while my regeneration is gone. Just be careful that the Prince hasn't brought his flaming sword with him, as that will certainly spell the end of it for the Trolls. If he's using the Lore of Nurgle, you have to stop him from buffing his own Toughness too.
1-2 Night Goblins Shamans with the Curse of the Spider God
6's to hit or not, they will still automatically wound the Prince if you roll them. This is the only way for your Savage Orcs or your Black Orcs to stand a chance against him. If you can get both poison and a timely spell of 'Ere 'We Go on the boyz, then you should be fine.
Not a favorite for many competitive Greenskins, but the big spider is still pretty useful when dealing with enemy monsters. The Spider should die in 3 rounds against the Prince, which means you have 16 spider attacks to roll enough 6's to kill it. If you can fight the Prince with a Night Gobbo block in the front and the Spider to the flank, then their Nets could keep the Spider alive for a 4th round, adding an additional 8 attacks. Better make that Poisonous Gland (D6 multiple wounds) count!
Do you feel like I'm missing an option? What's your preferred way of dealing with nasty, hard-to-hit monsters like the new Daemon Prince?