Two stars because I did keep reading and the end was a bit suspenseful. Much closer to one and a half stars though. I found the world building to be not as well thought out as people claim. Why does merely interacting with people of another blood type make the Delta Fever worse? I'm not sure I believe that enough and without that the whole tribe system falls apart. Also, where you are trying to create a different form of racism with blood type, why in the world leave a whole race separate and apart. That was really jarring, and exposed the hole in this fictional world.
It took me a long time to get accustomed to Fen's way of speaking. Instead of being immersed in her language and thus her world, I was constantly jarred out by the lack of grammar, and I'm not talking 'proper modern English grammar', every language, jargon, dialect, etc. has it's own grammar and I could never quite parse out the grammar of tribal speak. It reads more like an attempt at imitating a dialect rather then actually being written in a dialect.