@vincentric: The favor he called in was an army. So Eb literally raised a loyal army. They fought and died for him. As far as we know, they had no interest in Chichen Itza.
They showed up by the hundreds. Don't call it an army if you like, but many wouldn't call a bunch of pixies an army either.
Neither did the pixies. They showed up to protect pizza. Toot seemed a little nonplussed about Harry being in danger. The Kenku were just as loyal to Eb as the fairies are to Harry. It's all about debt and obligation. As soon as Harry owes them more than they owe him, the loyalty will be gone.
I mean, soldiers are paid (at least they have been for a couple thousand years. Read "Why the West Won" for a more complete explanation on the thesis that professional volunteer armies were the primary reason that Western Civilization survived and expanded rather than being eaten up by entities like Persia (who had armies primarily consisting of slaves and levies)).
Anyway, my point is mostly just that, historically speaking, armies are loyal to the ones who paid them—or, originally, the ones who ensured they were paid (via plunder). That was a big deal from the Marian Reforms in the Republican Roman period; he basically created the concept of a permanent, professional army that was paid in exchange for a term of service (they still got plunder, but they were paid salaries too). I think they had to serve for like 15-20 years or something like that, but if they survived, they were given retirement benefits. Also had professionally made, standardized equipment rather than "bring a sword if you have one."
The most immediate result of the Marian Reforms was that armies became loyal to their commanders. It basically set up the inevitable civil wars that caused the collapse of the Republic system. Julius Caesar (Marius's nephew by marriage, by the way) eventually took advantage of this, with Octavian really seizing the reins after his assassination.
Anywho, the point is that armies (good ones, anyway) render loyalty and service in exchange for payment. The Za Lord's Guard is Harry's standing "military" force. It even has a General (Major-General?) They expand the size of the force temporarily in exchange for additional pizza—if memory serves, Harry and Toot call it the Za Lord's Militia. The Guard is paid a regular salary, and has been receiving that salary since Storm Front. And Lea (or Mab?) made sure to continue paying them when Harry was dead. I think Molly covered it when he was stuck on Demonreach.
What Eb did in Changes is, I would argue, qualitatively different from what Harry did. It's closer to Marcone hiring the Einherjaren. They're Marcone's to command, but they're not his army. The Guard is most definitely Harry's, regardless of their motivation.
I think it's entirely possible (maybe even likely) that the Senior Council could call on forces similarly to Eb. But I don't think they have ones on tap. I mean, I'd expect they'd have done so in Battle Ground if they could have. But hell, the Merlin didn't even show up to fight personally (which I really would've liked to have seen).
On that note... what happens when Einrherjaren die in the mortal realm? Do they go back to Valhalla? Can they fight again? Do they have... resurrective immortality?
