The reason behind this build is to make The Mageslayer set work with cold Devastation. Build uses Olexra’s Flash Freeze to freeze enemies and then you drop Devastation on them and Trozan’s Sky Shards. For cold devastation Arcanum Frigus gun is needed. For shorter cooldowns the build uses huge cooldown reduction and Eternity relic. For spamming between spells and for healing with lifesteal Chain Lightning from component is used. Your main defense is freezing enemies, then lifesteal, Pneumatic Burst, Ghoul and Mirror. Build is a glass canon. In long battles you will have to take energy potions. SR 65-66 is relatively easy.
Build uses two green monster infrequent items - Terrnox’s Aether Tome and Stoneplate Greaves. Affixes are chosen for resistances. Two crafting bonuses are to freeze resistance and stun resistance.
image from the game with passive buffs + Pneumatic Burst
OK crit damage 43 %
big OA - close to 3300 OA
big cold RR, up to -122 % RR from OFF, Elemental Storm, Veil of Shadow and Murmur + Hand of Ultos
OK lightning RR up to -83 % from Arcane Bomb, Veil of Shadow and Elemental Storm + Hand of Ultos
OK life above 12 000 HP
freezing even nemesis with OFF (because of full Mageslayer set)
lower DA - above 2850 DA
up to 225 OA reduction to enemies from Veil of Shadow and Arcane Bomb
OK physical resistance 19 %
lower armor above 1900
high CC resistances
maxed resistances with reasonable relatively decent overcap
% damage absorption from Maiven‘s Sphere
healing on standby from Pneumatic Burst
Mirror of Ereoctes
Prismatic Rage from component
Build is capable of doing SR 65-66 relatively easily and a skilled pilot can go higher with it. But be aware of a mutator that increases enemy’s CC resistances in SR (with that mutator you will have to kite some enemies - without that mutator you can freeze them and they are OK). Build is not a total tank but can tank for a while. I don’t push my builds higher than SR 65-66. I don’t have a time number for Crucible because I don’t play it.
image from SR 66