I'm thinking along the lines of a one-off staff, which doesn't actually have any enchantment, but acts as a multiplier for the spells that you already have or get.
Might go some of the way towards mitigating the (constant) complaints that destruction spells are underpowered, and shouldn't be too much of a game breaker in that it only really would work well for mage type characters who already have (or should have) decent reserves of magicka and a range of spells.
