Corrupted Blood

Ok, I remember. That's why it would be good to cast it on your opponents if they are using marines, hydralisks, dragoons, ect. when you are attacking with melee units. When you close in, they are unable to hit you, and will take massive casualties while retreating to get out of the swarm before they can attack you again.

This can be very effective when attacking bases because defences won't be able to hit you either because they are considered range attacks, making all towers useless until the swarm wears off, but by then, your ranged units would have most likely destroyed them by then.

 

SmoothBore's idea is good, but instead of creating a plague like a Nuclear Launch, it should be something like that you have to upgrade a Defiler to Plaguer. This would be similar to upgrading Hydralisks to Lurkers, Mutalisks to Guardians or Devourers, and Zerglings to Banelings. It would be an extremely expensive upgrade, that would take a long time, and when it has finished evolving into the Plaguer, it should start with 0 Energy, and have to wait until it has something like 300 Energy before it can cast. This would not be a super-unit. It would not be an ultimately powerful unit, it would have the same health and armor as the Defiler, have Burrow, and would loose its other abilities (Dark Swarm, Consume, normal Plague, etc.) I don't think that it should slowly infect an enemy unit, but it should still be cast like how the normal Plague was in StarCraft1. It would effect a certain area, and after a few seconds, 5 - 10 or so, it would start to spread to other units. This would give the opponent time to quarantine the effected units, but in doing this they would become extremely vulnerable, because they are on their own without backup, and loosing health fast.

 

kay, but than it should be able to be upgraded while burowed

 

It isn't really an upgrade, it's an evolution, like Mutalisks evolve into Guardians or Devourers. It wouldn't be able to be evolved into a Plaguer while burrowed, because it has to form that egg in which it evolves. No other units can evolve while burrowed, so why should the Defiler?

 

i mean evolved while burrowed

 

Why should it evolve why Burrowed? There is no reason for it to begin with, and on top of that none of the other Zerg units that evolve can evolve while Burrowed.

 

yes but it is very vulnerable while evolving and you said it takes a very long time

 

That is one of its weakness's. It is defenseless for a long period of time. Otherwise there is basically no point in the evolution, because it would be invisible when doing so. Besides, if any unit was to evolve while Burrowed, it would be the Hydralisk to the Lurker.