Focus allows us regain our mana rapidly when we went overboard with Static Orbs without Mana Tunnel 1/1. The Desperate Meditation 1/1 node can increase our mana reg to well above 100 mana per second. A single point in Energy Overflow 1/5 is necessary to gain runes for our Runic Invocation. All other nodes are for survivability.
Runic Invocation is used for burst damage when fighting bosses. The Arcane Battery 1/1 node makes use of all the mana we spend and allows us to cast triple static orbs with Spell Cascade 1/1 whenever we please. This usually brings us below 500 negative mana where we start Focus to gain around 1500% increased mana reg (depending on max mana)
Monos and Bosses
For monos the gameplay is very straight forward. You Teleport on cooldown and use Static Orb after every Teleport and whenever you have excess mana. When out of mana you use Focus to get back to positive mana, so you can Teleport again. Minibosses can be nuked with Runic Invocation
For Bosses you have a fixed rotation. Teleport to proc Mana Tunnel 1/1 into Static Orb to gain enough Runic Energy 5/5 for the next Runic Invocation to proc Spell Cascade 1/1. This nukes the boss with three static orbs and a double Ball Lightning and usually leaves us way in the negative mana. Time to cast Focus until you have barely enough mana to cast the next Teleport and restart the rotation.
Defense
For defense this build relies on a combination of ward, armor, endurance and less damage taken.
We get endurance threshold from two places. Knowledge of an Erased Mage yields up to 9 endurance threshold per 10 missing mana and Cerulean Runestones 6/8 turns 30% of our max mana into endurance threshold. This means with around 1000 mana you end up with 1200 additional endurance threshold while being around 0 mana. This usually covers our entire health bar since we don't build too much health anyway.
Armor increases have a lot of synergy with Focus and its Iron Stance 4/4 node. While channeling Focus we sit at around 8k to 10k armor. PrefixExperimental Armour applies to Damage over Time on your gloves is a must have with this amount of armor. The spirits of fire blessing Grand Patience of Herkir might seem great for this build but in my opinion its a bait. I much prefer the Grand Body of Obsidian since you wont ever die from too few armor while channeling focus anyway. Being able to take some hits while not channeling is way more important.
We get less damage taken from a few places. Flame Ward is the most obvious one. Sadly we dont have permanent upkeep for this. The runemaster passive Sphere of Protection 8/8 grants us 8% less damage taken and has a similar theme as the Focus nodes Chilling Aura 5/5 and Shocking Aura 5/5. Prismatic Stance 3/5 is only used for leftover points in the Focus tree but its still nice to have. Sadly we cant really make use of Reowyn's Frostguard. But even without this we have around 48% damage reduction while channeling focus (59% when its and elemental attack).
Ward is mostly gained from Runic Fortress 6/6 which grants us 25% of our up to 10k armor while channeling after two seconds of channeling. Font of the Erased can be used as an emergency tool to gain a lot of ward on hit when we are low on life to quickly become stable again. Reactive Ward 6/6 is also there as in pretty much every mage build. Celestial Doom 7/10 also grants quite a bit ward on hit since every enemy is branded by Brand of Deception 5/6.
All in all this build is very defensive while channeling but will keep you on yours toes otherwise. Wrongwarp helps a lot with this since you have 1 second of leeway when casting outside of Focus. You should make heavy use of this one second when fighting bosses.
