Been suspecting for awhile this unique is bugged as a build that on paper excels at single target has felt very lackluster against bosses- initially just assumed I was going against resistent enemies but after some quick testing it seems something isnt working right.
The intelligence spark charge damage scaling on Fragment of the enigma doesnt seem to be working properly. On my character with 100 Intelligence, equipping FotE makes about the same tooltip DPS difference to spark charge as an obsidian scepter(55 adaptive spell damage) where it would be expected to give 200 added lightning damage, almost 4x as much added damage.
The More damage to spark charges applied by melee attacks affix doesnt seem to be working at all. I tried attacks with Mana strike(both with and without the ranged attack upgrade node) and charges applied via teleport, and damage seems pretty much the exact same in all cases- definitely not the 115% more damage my Enigma is rolled with.