I threw together a mid-Paragon tiefling fire elementalist without any serious high-op tricks one time. I was extremely impressed at how potent it looked just from picking pretty obvious stuff you'd want to do with any arcane striker.

(That obvious stuff being: Hellfire Blood, Primordial Adept (the fire one), and a fire-based Superior Implement rather than the Accurate one. For more fun, Rolling Thunder + Arcane Admixture works splendidly.)