Introduction
Very often I play with joke builds,which rarely sees the light of Grim Dawn forum.But this is little bit different.I have not played recently in SR,but decided to try this caster.It has two versions,first is straight chain lightning spam and second is little bit crazier,but both are resilient casters.
Chain Lightning Build
*perma buffs
Grim Tools https://www.grimtools.com/calc/62aEwBE2
Key set is the wonderful Cyclone set.In this version used Spelldrinker,which have nice proc,some flat elemental and energy absorb,not to run dry.Also Cindertouch gloves for proc and conversion.Massive RR in both versions.You can craft some pieces for stun,which is kinda low.
In SR died in 78 boss wave that Osyr temple priest,Slathasar,Maiden and Fabius.
On my way killed bosses like Mad Queen,Theodin,Kuba,Korvaak and others.
Here’s video from end of SR 77 
https://www.youtube.com/watch?v=-0md51z7bIQ&feature=youtu.be
In Cruci times are around 8 minutes.
Termite Mines more focused Build
Grim Tools https://www.grimtools.com/calc/qNYdDvWZ
Slight changes,go with Malakor for the proc and bonus to Censure,also amulet for Blast Shield modifier,gloves with bonus to Termite Mines.Also 2 parts Allagast set-ring+chest.
Some tweaks for both setups:you can take Giant’s blood and bound it to Blast Shield,Also you can remove BWC and put more points in Storm Box.
This build can do,but hard 170 naked(bufless),also can do SR 75.I tried face tanking the wave,but more sound strategy is to pull bosses one by one or in worst case,to fight two at same time.
Video from SR 75 https://www.youtube.com/watch?v=-oDTP6OHYpo
Conclusion
I don’t think its super optimized builds,but they are fun to play,also tanky.Cyclone set is good example for very good made set,with physical resistance,cast and attack speed,also flat damage and valuable skill point bosses.
does’t nerf mines 
And I play three classes set as not intended class combo,hope this build is not forbidden 