BEEP BOOP
These have a lightning projectile mortar barrage.
It deals low base damage and has a 6 seconds cooldown.
Since it's a mortar it does gain some benefit from AoE overlap.
They also use a lightning orb similar to ball lightning.
It has high base damage, 30% increased area of effect and can not stun.
It lasts for 6 seconds and will return to the spectre after 3 seconds, it has a cooldown of 5 seconds.
These have about 25% the life of a Primal Crushclaw.
They have 75% innate lightning resistance.
Overall,
The ball lightning can do decent damage when sat on top of targets, the long cooldown on both skills, combined with the bad ai, make these very clunky however.
They will only use the lightning orb when they are a bit further away.
They are also very squishy.
These can be found in T17 maps randomly, or the node Invasive Adversaries can be allocated on the atlas skill tree(Top side, just to the right of the Maven keystone).
This video was recorded in patch 3.24.