Mechanical Function
We play with unscaled Runic Invocation on the bar!
Cold/Elemental Damage over time is our scaler, however Freeze rate is what will turn the build from meh to whoa real quick.
Note: Twisted Heart of Uhkeiros is an option, but after testing found it wasn't necessary for general play.
Our Frost Wall is our primary damage source, however, we also apply significant amounts of Frostbite ourselves (especially if you acquire T7 cast speed). Frost Wall is also triggering our Flame Ward which gives us 1000 armor thanks to Frostguard, and Warmth to help alleviate any mana issues you may come across. This is normally not an issue however, you may elect to put into the 4 points from Warmth into (3) Concentrated Shielding and (1) Fortification if you don't quite have the ward retention down. This will add significant ward for every wall we walk through.
Mana for us should be solved rather quickly because of how we scale Arcane Restoration. This way you can have enough mana to walk through as many Frost Wall as you want.
The rate at which Frostbite is applied by our Frost Wall is impressive. It becomes more impressive when we add a hard rolled T7 amulet with SuffixChance to Shred Armour on Hit. This is thanks to our passive Freezing Point, where we convert all shred to "frostbite chance". There is a very good chance you can just casually walk around through walls and it will clear for you. You may have to Flame Rush into a rare pack or monster from time to time. However the double branding + your Glyph of Dominion + Frost Wall's Runebolt + your Runebolt should tear up ANYTHING quickly. Considering our Frost Wall has a +200 base spell damage (assuming you have at least 2000% freeze rate) this all will happen fairly quickly with Frigid Domination.
Since our Glyph of Dominion is automated with our Flame Rush, there's no real reason to have it on the bar. Normally, this Glyph of Dominion would go on CD on use because of the node Runic Dominance, we get to ignore that because of Flame Rush. This is also why (if possible by sealing affixes of SuffixFire Resistance) in our gear, however it is not by any means the end all be all. We do this because of the node in Flame Rush, Blazing Flux, which would give us an 18% CD reduction. Don't break the bank to do this however, this is just a bonus.
Defensive Mechanics
As per standard for our Runemaster's, our defenses are achieved through capping SuffixCritical Strike Avoidance and generating ward through offensive measures. This is no different here. We add a large chunk of armor from our Flame Ward's Frostguard node. This damage reduction from the armor it supplies, plus the damage reduction from our passive tree Mental Catalysis and Sphere of Protection help reduce this damage further. It could be argued that if you achieve 100% critical strike avoidance, that you can drop Mental Catalysis and push fully into Sphere of Protection, or even more into the Sorcerer nodes Cryomancer and Chill to the Bone could be a better option. However, I find it cumbersome to be 100% CSA, so this protects us "just in case" a crit strike hits.
Basic Engagement
Almost all engagements will be similar in nature.
Cast Frost Wall and walk, while avoiding the obvious incoming damage. Use Runebolt from time to time to re-up mana loss, and clear larger packs with Flame Rush. (Stay in the Glyph of Dominion when it's feasible, as this is pouring in 100's of ward per second into you, and you are attacking with more Runebolt as well. If in danger, Frost Wall and Flame Rush or walk through it and re-engage.
Difficult Engagement / Bossing
(See Orobyss Demo Video for example)
Put on your "pocket" Throne of Ambition. If you have enough damage, this may not even be necessary.
Walk through a few Frost Wall and even pop a Glyph of Dominion to charge the ward batteries.
Engage with Frost Wall and Flame Rush through the enemy in order to apply a double brand. Make sure to walk through your wall in order to take advantage of the Decree of the Burning Wind. Rinse and repeat as necessary until desired results are obtained.