Hypersmurf
Moderatarrrrh...
Sure Strike is not a power that deals damage when it misses. When it misses it is a power that deals no damage. Ergo, if you have an ability that keys off a power doing damage it will not apply if the power does not.
Such when Stinking Cloud its targeted against multiple creatures it indeed is a power that targets multiple creatures. But when it does not, then it indeeds is not a power that targets multiple creatures.
And since then it is not a power that targets multiple creatures and it is an area power it must be a power that causes an obstruction when not cast onto multiple targets.
If we divide Powers into "Powers which deal damage" and "Powers which don't deal damage", Sure Strike is a power which deals damage.
If we divide Area Attacks into "Area attacks which affect multiple targets" and "Area attacks which create an obstacle", Stinking Cloud is an area attack which affects multiple targets, and Wall of Fire is an area attack which creates an obstacle.
-Hyp.