So far only the direct damage spells (and not even all of them) get a bonus from shards with the corresponding element. This way the elemental type of the shards you control are not very important, and neither is converting them to your element (with the corruption spell for instance).

To make the shards more important they could give different bonuses to most of the spells.

i.e:

• +1 level for summoned creatures for every shard with the corresponding element
• +1 turn duration for certain debuff spells for every shard with the corresponding element
• etc...