LoD Mammoth Hydra Wizard Skills and Runes

Active Skills
Spectral Blade Barrier Blades Black Hole Spellsteal 1 Teleport Safe Passage 2 Blizzard Unrelenting Storm 3 Hydra Mammoth Hydra 4 Storm Armor Shocking Aspect
Passive Skills
Galvanizing Ward Elemental Exposure Arcane Dynamo Audacity

You will start runs with an activation of Storm Armor, which is to be kept up throughout the rift. Once you come across a decent pack of monsters, prepare the pull with a Black Hole to clump them up, then close the distance — either by walking or engaging with Teleport — in order to trigger the bonuses of the Audacity passive. Then, pre-cast a Blizzard to trigger the bonuses of Winter Flurry, and buff up your Fragment of Destiny effect and Arcane Dynamo passive with Spectral Blade prior to summoning Hydras. Re-buff and re-cast Hydras manually as they expire.

Your primary damage dealing skill and namesake of the build is, of course, Hydra. In the LoD version of the build you are not constrained by the Typhon set limitations of multi-headed Hydras, and you are free to take the highest damage dealing rune of the bunch — the single-headed Mammoth Hydra.

You will be taking Blizzard by necessity due to the revised powers of Winter Flurry — now transformed into a Hydra-specific source that amplifies the summons' damage against enemies within the Blizzard radius. To extend this benefit and minimize these supplementary casts, you will be taking the longer lasting Unrelenting Storm rune.

With the revised powers of Fragment of Destiny — now improving the damage of Hydras with a stacking mechanic depending on Spectral Blade, you will have to include this primary attack by necessity. The rune of choice is Barrier Blades, which supplements the shield-based protection of the build and synergizes nicely with Ashnagarr's Blood Bracer.

Black Hole will be taken into the build as means of crowd controlling the enemy and building up large pulls. You should take the rune Spellsteal, as it offers a good balance between increasing damage against, while decreasing damage from, enemies that are afflicted by its radius.

Sometimes immediate repositioning will be required — evading a bad affix, engaging a larger pack of enemies to maximize the Mammoth Hydra AoE, or simply to gain a temporary Toughness buff in a rough fight. Teleport will cover you for all these purposes, along with the damage reduction of the Safe Passage rune.

Rounding skills out, you will be adding Storm Armor to the build. With a fire-and-forget duration of 10 minutes and a negligible damage proc, it can be easily overlooked if not for the massive damage reduction properties of Halo of Karini (see this build's gear page for more information). You will be taking the rune Shocking Aspect for the superior uptime of the procs for the Karini buff. Alternatively, you can consider Scramble for the additional movement speed.

This concludes the overview of the Active Skills, now let us look through the Passives.

Arcane Dynamo offers a whopping 60% multiplicative increase of your next spender with fully stacked Flashes of Insight, enforcing a rotation of Spectral Blade stacking (both this passive as well as the Fragment of Destiny effect) prior to putting a Hydra down.

Added with similar reasoning to Magic Weapon Deflection (mainly Squirt's Necklace buff maintenance), Galvanizing Ward introduces a solid damage buffer that benefits from the doubled effectiveness via Ashnagarr's Blood Bracer.

Audacity brings a sizable 30% multiplicative damage increase against enemies within 15 yards — a near-melee range prerequisite that you fulfill naturally through the playstyle of the build, as enemies close in on you while you channel.

Elemental Exposure rounds out your passive selection with a final, decent damage increase. Notice that the passive bumps damage in 5% increments per element used; you fulfill the fire with Mammoth Hydra, cold with Blizzard and arcane with Barrier Blades. The final bump will come from the damage type of your weapon, Serpent's Sparker — a lucky roll (or reroll) of the base damage from another type (i.e. physical or arcane) into lightning will bring the last piece of the damage buff.