Examining the conversation
This is going to be huge. Drethnor has decided to blow ALL his points on one huge action. Twenty Two points are going to transform 15 scavengers into something else entirely, a new intelligent race within the world. It's huge, and it's going to totally change the course of this game. Which it should given that 22 points for an action is a MAJOR earth shattering thing this early in the turns.
However what is really important to notice here is the way the players previous actions and experience effected the point costs. Drethnor's first major action was to alter an animal and so he knows how it's done, he's also got a connection both to the people and to the vultures which made him familiar with how both species bodies work lowering the cost again, plus he's not simply giving them things, he's copying all the changes from animals in the environment that he and his people have seen, vultures, owls, lions, and of course people.
If another deity had done the same thing the point cost would have been MUCH higher. This might be a 40 or even 60 point action for another deity. What you do and HOW you do it counts for a lot. Every player starts out the same, but over time you define yourself. Drenthor is very into animals and domestication, he's also very into birds. If he's wanted to create Lion-Men instead he would have been out of luck.