http://www.arenajunkies.com/topic/13...0#entry2233756

Clos makes the spells "miss" not "resist", it is not affected by spellpen, it is affected by "hit".

This is also the reason that makes clos fail 100% of the time for mid-air spells.

The games checks if the spell is hitting or missing when he is lauched, not when he hits the target (it's pretty obvious since the animations are different).
If you remember in BC clos was "resist", and didn't fail for "mid-air" spells because the "resist" is checked when the spell hits.

One a side note there is exactly the same problem with detterance, before it was changed to 360 deterrence worked for mid-air spells, now it doesn't work anymore because the animation has been changed to "miss" not "deflect".

TLDR: na wotlku nie je možné cloaknuť letiaci spell