Those last two volume really make the story going forward, in the first three books I feared it wouldn't. The war scales are in another dimension, Regis status is moving, the relationship become clearer and active. Even the world/country is changing.
Really enjoyable, and it also feels like a little darker.
Also while reading I really thought : Sky should get a french editor, seriously... the little french there is is fucked xD
Yeah yeah, I could, but no time. And couldn't find back the french bits to fix here.