[Frost Prime] build focused on stacking armor both to be generally durable, as well as to optimize the benefits of Icy Avalanche's extra armor-scaling Overguard.

What Arcanes should I run? If you want higher Overguard potential, run Molt Augmented in the free slot. If you want to optimize freeze time run Arcane [Ice Storm].

Why not [Archon Flow]? This build focuses on Overguard Stacking (hence, [Precision Intensify]), and [Frost]'s abilities aren't necessarily suitable for killing enemies to begin with. Avalanche itself might do reasonable enough damage to kill it, but then you have to contend with it being a 10% chance, and having a 10s cooldown upon being triggered.

If you really want personal energy generation, you can subsume Lycath's [Hunt] or Dispensary over Ice Wave or Snow Globe, run a [Dethcube] with [Energy Generator], a Zenurik Operator can drop a Wellspring, you could run a Primary with Primary Exhilarate, or a [Glaxion] with its [Photon Overcharge] augment.

What Archon Shards should I run? My primary recommendation is to have at least two Amber Shards (Casting Speed), 1-3 Crimson Shards (Ability Duration), and 1-2 Azure Shards (Armor).

For an alternative build (assuming you have energy generation covered), you can replace Arcane Energize with Arcane Battery, use two Violet Shards (Melee Crit DMG), 1-2 Amber Shards (Casting Speed), and 1-2 Azure Shards (Armor). You would lose out on the extended freeze times from the Duration Shards, but could better supplement melee combat with powerful Crit Damage bonuses, allowing you to drop [Organ Shatter] from your typical melee builds.