This build uses 2 key abilities: Molten shell and an unique item called Aeagis Aurora
This shield returns 4% of armor as energy shield on block. Seems pretty mediocre, right? Not when you stack enough armor and pop some granite flasks! If you have enough armor + granite flask + bonus armor during duration you have 40k+ armor, which means a single block can return 1600 ES! Without a granite flask you should restore about 160-180 ES. Seems kinda mediocre, but considering you will still restore ES while molten shell is absorbing damage, which should prevent you from dropping to low.
With this build you have 70% block chance, and with the right unique and passive you block 45% of all spells as well.
Not only that, but when you spam molten shell you can absorb 1900 damage if you use it in combination with 30% bonus to buffs passives. These two things combined allows you to go CI, which makes this build even more... interesting.
On top of that molten shield does a huge amount of AoE damage (~950 - 1350 fire damage on lvl 18). Combined with the right gems, passives and items you can make this attack deal 1800 aoe dmg at the very minimum against max resistance mobs, imagine how hard it would hit if it dealt max damage against no resistance mobs... and then ignite them
5L: Molten shell, Fire Pen, Iron Will, Mana Leech, Chance to ignite
Why you want to use molten shell is really obvious, but the ability uses a ton of mana, so we need to use gems that gives the most bang for buck.
Fire pen is used to recuded max resistance of a boss to minimalize minimum damage, iron will because you have a lot of strength, and chance to ignite because the damage you deal is so huge that this proc will pretty much mean a death for most rare mobs. Finally you want to use mana leech because it refunds 100+ mana with the massive amount of damage it deals.
4L: Ice nova, faster casting, cold pen, iron will
Ice nova is my favourite secondary ability because it allows you to slow all the mobs next to you, recuding the damage you take or it allows you to GTFO when necessery.
Support gems have pretty much the same explanation as for molten shell
4L: Determination, clarity, discipline, reduced mana
Self explanatory (don't push clarity to much if you dont have the mana)
4L: Tempest Shield mana leech, iron will, reduced mana
Tempest shield gives you 5% more block, as well deals some damage when you block. It is a self buff that reserves mana, so we really can't get away with using support gems that increase mana. Thats why i went with mana leech so you get some bonus mana, iron will to get some bonus dmg and reduced mana to decrease the cost.
Decoy totem, enfeeble, enduring cry
Rewards 4% of armor as ES when you block
Increases spell damage by 35% and increases radius of molten shell explosion by 10%
Stone of Lazhwar:
Necklace, 50% of block applied to spells, increased cast speed, extra mana
Can't be frozen, 20% increased mana, mana regen
27% more fire dmg
Focus on high armor/es gear and maxing resistances
How to play:
Max endurance charges, refresh molten shell as soon as it drops, keep enfeeble up, spam ice nova when molten shell doesnt need refreshing and enfeeble is up