Those familiar with Exalted will get this, those who aren't can go look it up. Those who are familiar with Exalted will probably disagree with me about this premise. You are wrong.
My premise? The Deathlords should never be played "Smart" they should never "have read the Evil Overlord's List" or any variant of that logic. Yes they are inhumanly brilliant, yes they have more powers than your character ever should have, No they shouldn't be played like munchkin pcs even if that's what they are running against. No they shouldn't be efficient world destroyers and that's why they need to be nerfed mechanically.
Deathlords are at the beginning and end of it GHOSTS. Ghosts in Exalted are creatures of lost passions who try to fill in the gap with memories and drama. The only thing that keeps a Ghost out of the Lethe or Oblivion is their passions. Their hates, their loves.. the single greatest danger to any ghost is BOREDOM.
You know what's really boring? Winning all the time. Crushing bugs is fun.. for a few minutes.. centuries later you want something resembling a challenge. That's what the Deathlords are at. They aren't "threatened" by your solar or dragonblood or Sidereal or Lunar thwarting their plan or beating them until they respawn in the underworld.. no THAT'S WHAT THEY DEEP DOWN WANT! Conflict, they want an enemy they can explain their complicated plans infront of they want to spend months plotting revenge after your character saves the East. That's what they really want.
Because if they really were purely efficient world killers they would have succeeded by now, they wouldn't have fought over Stygia they wouldn't even need abyssals. They do this to Exist, because deep down that's what all ghosts really do.(Yes I understand the Paradox of people built to destroy Existance care only about Existing, but that's ghosts for you)