I use almost this, but instead of Frost Wall I have specced in Flame Ward, and Spellblades ability to summon Flame Wards more often. Fire damage on it, and just Flame Rush in on a pack and see them burn. If needed activate Flame Ward for a little bit more damage.
I have also locked down Runic Invocation with Immutable Order. So one Hydrahedron from Flame Rush, hopefully one from the relic and if needed one more on activating Runic Invocation after three shots with Runebolt. Everything in melee range.
Fun stuff!