Yes, Monsters eat humans (without human blood they weaken and eventually die), Zombie plague happens, Monster’s risk exposing themselves to stop the spread of the infection. Zombie blood lacks the proprieties that sustain the Monsters so they can’t eat them. It’s actually the same reason Zombies eat humans.. for the same property.. the addiction is just so extreme that it overrides all other brain function including survival instinct. In the end we learn that the plague came from monster blood that has been experimented on.

The human is immune, unlike any other human they’ve seen. He wants to deliver the human in the hopes that a cure can be found. The griffin is on one of many teams that are trying to stop the spread of the zombie plague, but IF a cure can be found that would be a MUCH better solution. Him bringing that about would get his family line back in the good graces of the Council. In the backstory there are few Griffins so they don’t have a seat on the council like the other 9 species of monsters. The Griffins act as enforcers for the Council’s laws and agenda. The main character has been through training to be an enforcer but was not allowed due to his father’s disobedience (shame), but when the zombie plague broke out many more teams were needed to fight the spread of the disease. Other monsters were added to the teams and any griffin with training was called up, this has given him his chance. Finding the immune human is exactly the thing he’s been looking for and in the beginning he’d risk anything to deliver ‘her’ to the council. He’ll do ANYTHING to prove his loyalty. This is the character arc. At the beginning he’ll do anything, risk anything, even his teammates’ lives, to prove his loyalty but then learns along the way that there is value in doing what is right in the face of loyalty and ‘orders’ (just like his father did).

There is a lot here.. I get that. It’s a big world with a crazy amount of backstory.. but even if it was all just humans and in the middle of the zombie outbreak you found someone who has been bitten and doesn’t turn (immune) you’d want to want to figure out why or get her somewhere that they can figure it out, in the hopes of finding a cure.

A desperate griffin and his team of monsters are ordered to fight through a horde of zombies to save an immune human with the hopes that a cure is in her blood.?