Can a 'Blade Barrier' turn?

Question

The Blade Barrier spell can be a Wall or a Ring without stating if the Wall has to be a straight line. Can the Wall have a curve or a turn in it?

Answer 1

No.

Blade Barrier's effect line lacks the Shape-able (S) tag. This means that its shape cannot be changed and so it must be either a straight line or a circle.

By contrast, look at the effect line of Wall of Stone. There, the (S) tag means you can shape its area (see the magic section of PFSRD) within the limits stated by the spell.

(S) Shapeable
If an area or effect entry ends with “(S),” you can shape the spell. a shaped effect or area can have no dimension smaller than 10 feet. Many effects or areas are given as cubes to make it easy to model irregular shapes. Three-dimensional volumes are most often needed to define aerial or underwater effects and areas.

Answer 2

It doesn't say and there's no official effect definition of "wall." I would tend to rule that it must be flat, because it seems cheesy to stack it thick or whatever to create a "zone of blades" - that would be a higher level spell in my estimation!