Regarding your class: It is really well done, and combines two really neat homebrew base classes that deserved to be combined. The total set of class features seems small, especially the last two levels. Lots of class features depend numerically on the class level, so this should't be too bad. But something at 10th level would still seem to make sense. An obvious ability for 10th level would be something that made it so that levels of other classes and PrCs which advance grafting also count as ozodrin levels for purposes of total Form Points.
Also, it may make sense for Strange Bonds to be (Su) rather than (Ex) given what it does. Feels more supernatural than extraordinary.
Sense Seeds may need to specify the level of accuracy that one gets for the distance and direction. Also, what happens if the target is on another plane?
Shadow is a proper noun here, right? If so it should be capitalized.The shadow of the black forest on the other hand seemed to seek improvement of what was once a pleasant and safe forest an hours ride from a quaint town.
I'm not sure I'm parsing the second sentence correctly, but I don't understand what it means. It seems like a very roundabout and awkward was of saying that everything can easily kill people. Maybe you mean something like "It is said that every living thing there is capable of killing a normal man with ease, even things like squirrels."Due to his work it came to be considered a dangerous place where abominations roamed and men might emerge something else. It is said nothing in there is incapable of killing a normal man with ease, not even things like squirrels.