I disagree - I suspect this story is breathing room for the author to work around the changes in power level/situation that he has written his hero into - a straight up detective case with a few twists. While his new role makes him more rock and roll, it also brings out new, tough enemies (cough Elder Gruff); but doesn't put him over to top on extant foes Cowl, or Council members.
Plus as his mentor reminded him - it is all about his own choices. His role remains autonomous; he can defy the Winter Queen; and unlike Slade, he has enough juice that he can't simply be pushed around. (Plus the open question of his role as the guardian of Demon Reach, Lash possibly returning to his slowly recovering brain-pan, etc.)
Shayne
(Possible spoilerish stuff in white)
Plus as his mentor reminded him - it is all about his own choices. His role remains autonomous; he can defy the Winter Queen; and unlike Slade, he has enough juice that he can't simply be pushed around. (Plus the open question of his role as the guardian of Demon Reach, Lash possibly returning to his slowly recovering brain-pan, etc.)
Shayne
(Possible spoilerish stuff in white)