I believe that Destruction is generally considered the bread and butter of most offensive minded mages, correct? The use of elemental magic seems the most practical means of harnessing magic to attack one's enemies, especially in situations where Conjuration would be either impractical or dangerous to the caster. But considering the various ways of counteracting conventional spells - reflection, absorption or outright resistance - wouldn't more experienced users in Destruction seek out a more advanced means of engaging their opponents? After all, magic is about playing with how the universe works, so one would think there are more advanced applications for Destruction than making a bigger, stronger fireball.
Would it be conceivable for a mage to use their magic in creating plasma, for example? Even a small amount, properly contained and manipulated, would not be affected by the sort of spell resistances that might make elemental magic ineffective, and would cut through armour like a warm knife through butter. Alternatively, would it be possible to saturate an area with enough frost magic that, even without hitting one's opponent, the sheer cold would kill them? It just seems unlikely that highly practiced Destruction mages would leave themselves open to the possibility of having their spells bounced back into their faces.
I appreciate any insight you fine individuals may be able to offer on this matter.