I don't follow more than a couple of Marvel books, none of which feature the X-Men or Inhumans, but I did read IvX #0 and #1. After reading them I have to wonder; how does anyone not think the Inhumans are the bad guys here? Since I don't read the books maybe I am missing something and if so please set me straight.
From what I gather the Inhumans released the Terreigen Mists into the Earth's atmosphere which split into a couple of clouds which drift around the Earth. As those clouds wander the Earth the kill most of the mutants they come in contact with. In addition to killing mutants they turn the some of the world's citizens into super-powered beings. The mutants, in an effort to fight off extinction, destroy one of the clouds and the Inhumans go crazy. I realize mutants are not liked by the average citizen but most superheroes and superhero teams know better so why aren't most of them jumping to the X-Men's aid? Are they ok with mutant genocide? Are they OK with mass numbers of people being randomly mutated? Further, I can't imagine there is a single world government that is OK with the clouds randomly mutating their citizens. So why do the governments and agencies like S.H.I.E.L.D. not work against the Inhumans to destroy the clouds as well?
This story line, much like Civil War II (which I have, unfortunately, read) seems poorly thought out and executed.