Interesting character revision. About problem “Why would the other champions accept a pyreen?” - others can even dont know “what is pyreen” or “how to recognize”. Even champions arent omniscient about each other 
Another good point would be in rivalry about Gulg and Nibenay. Shadow King can know, that Lalali can have untypical powers, therefore he don’t want start open, full-scale war. He know, that in theory Gulg have lesser potential and he should win normal war, but “Forest Godness” have some big tricks, unknown for him. And he have some fear.