jgsugden
Legend
6 enemy undead PC types riding 6 undead wyverns?
Versus a level 11 party?
If you're looking for something in the EL 14 to 15 range (very, very tough battle), you'll want the CR types and the undead to all be between 5 and 10 with an average around 7 or 8.
I'd start by using modified fiendish wyverns. Those would be CR 7. Replace Smite good with a 1/day breath attack of poisonous gas [DC17F - d6con/d6con]. Make the general's wyvern be an advanced version (huge size, 9 HD, CR 8). The undead look is fine for a fiendish creature.
For the PC types, I'd go with 3 CR 8s, 2 CR 9 and a CR 11.
The CR 8s would be 7th level PC types with a template applied with an LA of +1. I'd go for archer types in this spot. Perhaps ranger/barbarians for all three?
The 2 CR 9s should be spellcasters with the same template. One arcane and one divine/druid.
Cloron Shattersoul should be a barbarian type with the same template. He is an orc, after all. The trick here is to make him appear really nasty without making this encounter too hard for the PCs to have a chance. This can be acheived by using a fatal flaw in the general. I'd make him a 14th level barbarian, but rip off one of his arms. This reduces him to 1 handed weapons with no shield, a significant burden for a barbarian. As a further issue, I'd make him defensively minded: Have him hold off in combat until most of his allies have fallen or the PCs come to him.
Alternatively, you can go with 6 separate encounters of EL 11 to 15, but that just feels fake. It is best to have the enemy 'party' act like a party, even if it means reducing their power level accordingly.
Versus a level 11 party?
If you're looking for something in the EL 14 to 15 range (very, very tough battle), you'll want the CR types and the undead to all be between 5 and 10 with an average around 7 or 8.
I'd start by using modified fiendish wyverns. Those would be CR 7. Replace Smite good with a 1/day breath attack of poisonous gas [DC17F - d6con/d6con]. Make the general's wyvern be an advanced version (huge size, 9 HD, CR 8). The undead look is fine for a fiendish creature.
For the PC types, I'd go with 3 CR 8s, 2 CR 9 and a CR 11.
The CR 8s would be 7th level PC types with a template applied with an LA of +1. I'd go for archer types in this spot. Perhaps ranger/barbarians for all three?
The 2 CR 9s should be spellcasters with the same template. One arcane and one divine/druid.
Cloron Shattersoul should be a barbarian type with the same template. He is an orc, after all. The trick here is to make him appear really nasty without making this encounter too hard for the PCs to have a chance. This can be acheived by using a fatal flaw in the general. I'd make him a 14th level barbarian, but rip off one of his arms. This reduces him to 1 handed weapons with no shield, a significant burden for a barbarian. As a further issue, I'd make him defensively minded: Have him hold off in combat until most of his allies have fallen or the PCs come to him.
Alternatively, you can go with 6 separate encounters of EL 11 to 15, but that just feels fake. It is best to have the enemy 'party' act like a party, even if it means reducing their power level accordingly.