Rdan, I actually agree, mostly, but the problems come into play with the timing of this spell, which is the core of the problem. This and the fact this spell seems to be an example of a sloppy or confusing use of "Duration, Range and Area of Effect.". . .people see the duration of "-" which makes no sense,
I agree that "-" should be "varies" as the text description clearly indicates. I do not think there are problems with Range or Area of Effect.
1) First "Duration"
Cast the spell, apply it when the attack(s) come(s). Canceling actions does not allow casting a spell, even an instantaneous spell, so RAW does not allow Bladeturn to be cast unless it was declared. It might be reasonable to house rule that instantaneous spells can be cast with a Cancel Action, if a SCSM with a -10 is made. (Still requiring that 60% action remain in order to act after canceling an action.) I think this is all pretty clear, given that the "-" must be overruled as not matching the spell description and notes. I think it was probably from thinking that the duration of the effect of an individual bladeturning was instantaneous, and not taking into account the space between casting and the attack that is turned or the multiple turnings that a single spell can cause.
2) Next is "Range"
Can we agree that two things are going on here, casting the spell is one thing, selecting an attack to block is a second thing?. . .with the multiple deflect + concentration thing the deflect could happen many rounds after the spell is cast.
Two things, yes. Two actions, no. Or rather, the second action is "concentrating on the spell" rather than "selecting an attack". I see no reason no to allow selecting two attacks during the same Phase to be turned, which would be impossible if the selection were regarded as an action in itself.
Range is the distance the spell can go before it resolves. . .these spells all have similar effects, they grant the caster the ability to selectively deflect missiles or turn melee attacks. . .i.e. the casting of the spell, grants an ability.
This argument also suggests a range of "Self" for Fire Bolt: The spell that gives you the ability to shoot a bolt of fire from your hand.
3) Finally "area of effect".
This is the area covered or the distance the spell can go AFTER it resolves (i.e. once the casting roll is made successfully).
Using the example of Deflections III off of Essence Shield Mastery, you may deflect a missile that passes within 100' of the caster. . .So the ability granted by the spell, to deflect missiles, covers an area 100' out from the caster once the spell is cast, and now active and ready for use. . .so area of effect is "100' radius"
But it only affects a limited number of missiles within its range of 100'. It does not affect the area, but a very, very limited subsection of it. I cannot agree with this relabeling.
The issue seems to be people's reading thrown off by the selection of targets after casting is done, but this is no different than the way "React and Melee" works. You do a general indication of activity during declaration, but pick out the target(s) later. This does not change the entire area covered by the range into an area of effect any more than every potential target of a React and Melee is the target of the actual attack. At this point, however, we are no longer arguing interpretations of spell effects or mechanics, but quibbling over the somewhat nebulous terms "range" and "area of effect", which cannot mean exactly the same thing for each of the wide variety of spell effects offered in Spell Law.