Journeymanmage
First Post
Int/Dex so it's already fail right from the start.
Don't boost Dex then ....
Buy up to a 12 or use a racial +2. Never boost. The "2ndary" at-will, no action effect does "dex damage and a carrier". If you use the 2ndary on a minion, 1 or 100 points of damage, it doesn't matter, the minion is gone. If you use the 2ndary on a non-minion, the carrier (-x to hit, slowed, combat advantage) can be more important than the extra damage.
Story-wise, Dex/Int makes sense. They're a Bladesinger. Elven agility and grace (dex) combined with their ancient knowledge of the Arcane (int).