My complaint regarding Nabu has always been... and likely will always be... not just what he does, but what he does not do.Doctor Fate is a hero.
A harsh, uncompromising hero (but so is the Batman), who fights terrors and monsters most heroes cannot even begin to imagine (so do the Green Lanterns), who has been doing this for years and decades and centuries. He is the way he is because he is an emotionally neutered machine dedicated to order at the cost of niceness and because he has one of the worst, most thankless jobs in the galaxy (not that he needs to be thanked, Fate does what Fate does because he must do this. It is, after all, very metaphysical.)
He is, however, in utter opposition to the protagonist, which makes it easy to see him as just another soulless villain. But that's the tragedy of it, he's not. In a better world, Giovanni Zatara would be happy to work with Nabu to fight these things because, well, someone has to and it takes a mighty sorcerer to do so. But neither -16 nor ours are good worlds.
Paul offered Nabu thirty Atlantean volunteers... and Nabu reacts as if that would work.
Nabu could have done that himself months ago. This isn't just theory anymore. I don't scorn him for Order, I scorn him for allowing his own sloth to harm good people.
I'm unhappy with Siskin's apparent death too... and Teekl's, in fact. Terror Thing contact has driven people to use lethal force before, and Nabu can use a lot of lethal force... an escape route would have helped, I think.