Intelligence Stacking
This build takes advantage of Intelligence stacking on every piece possible. Intelligence grants every damage skill 4% damage as well as 4% ward retention. You are also granted 3% increased critical strike chance per point of Intelligence because of Calculated Destruction 5/8 and also 1% cooldown recovery rate per 4 point of Intelligence from Ancient Inscriptions 8/10.
Single Target
Lightning Blast is one of the highest Single Target Damage Skills because of Convergence 1/1 allowing a single cast to be chained to the same enemy up to three times for four hits total per cast. It also has one of the best skill trees granting many more multipliers such as Shattershock 3/3 and Frontloaded 4/5. It also gives easy access to Lightning Nova granting an additional 25% less damage taken defensive layer. This also enables the use of four large idols PrefixIncreased Cast Speed while you have Lightning Aegis for up to 76% increased cast speed. The major downside of using Lightning Blast for single target is the high mana cost combined with the high cast speed deleting your mana very fast. This is solved by the usage of the unique boots Foot of the Mountain which grant -6 to mana cost of skills after standing still for three seconds putting Lightning Blast's mana cost to exactly zero. Standing still isn't much of a problem in boss fights as you can still reposition yourself using teleport which does not count as movement and therefore also does not break the mana cost reduction of the boots. Also after acquiring Twisted Heart of Uhkeiros you can also face tank lots of content by generating ward up to ten thousand.
Mapping Clear
Elemental Nova is used for clearing as it has decent AoE and damage as well as being procced three times for free on every Teleport cast using the nodes Elemental Dawn 1/1, Elemental Dusk 1/1 and Elemental Midnight 1/1. Elemental Nova's mana cost is reduced to 2 mana by a combination of Cryomantic Fragility 4/4 and Glacial Might 3/5 for a smooth experience while mapping. If you have higher mana regeneration you can also put more points into Glacial Might for more damage. As Elemental Nova is an area skill it also takes great advantage of the newly introduced Runemaster Passive Node Edict of the Scion 6/6 granting 146 Ward every cast in combination with Arcane Focus 8/8. IMPORTANT: DO NOT SKILL EITHER Lightning Nova or Fire Nova AS THIS WILL CHANGE THE RUNE YOU WILL GET FROM Immutable Order 1/1.
Layer of Defenses
The backbone of this build is autocasting Runic Invocation by using Num Lock. The Invocation is based on the first three elemental Skills on your hotbar by using Immutable Order 1/1. The invocation that we will be using is Reowyn's Frostguard granting 30% less damage taken from all sources and generating a burst of Ward and then smaller amounts of Ward every second for 13 seconds. To use this specific Invocation you need the combination of cold → fire → cold in your hotbar. This is achieved by using cold converted Lightning Blast using the node on the basic mage passive tree Rune of Winter 1/5. The fire spell is Flame Ward followed by Elemental Nova with only Ice Nova being enabled for the last cold skill. Both Teleport and Runic Invocation do not count for Immutable Order 1/1 so you can just place them anywhere on your hotbar as you like.
Flame Ward is also purely on autocast as Runic Invocation. By having high cooldown recovery rate it gives a relative high uptime of its own 30% less damage modifier as well as its nodes Barrier 5/5 and Prismatic Buffer 3/3. Additionally, it is also used to generate Haste by using the node Flame Runner 1/1, which will then get prolonged and kept up permanently by Teleport Node Comet Rush 4/4.