The season premiere makes clear how much ground the show has to cover in only 13 episodes. - From A.V. Club
Will the show bend over backwards to resolve its umpteen plot threads, or will it burn them all away to produce a glorious and centered final season?
The shattering of Hadrian’s Wall and Black Claw, Diana’s ability to kill off enemies with the power of her mind, and twin resurrections by the Splinter of Destiny are all big developments, and Team Grimm is battered around by all of them.
The episode is a bit bowed by its obligation to introduce a new status quo, especially with the knowledge of an end date that means it could be the last one they ever do.
Some of that disjointed nature comes from the fact that the Splinter of Destiny, having brought Nick back from the dead, has to take up the majority of their focus that isn’t devoted to survival.
The other locus of power that Grimm now has to deal with in full is Diana.