Shakespeare, Tesla, Bride of Frankenstein, and just a touch of Independence Day.

These tall, blue skinned figures have large black almond shaped eyes with black hair constantly standing on end always appear in trios or covens of six or nine. They communicate via electric signals sent from their long, spindly fingers to one another. They constantly levitate, unaffected by terrain.

They are always found in trios or covens of 3,6,9 or even 12 hags.

AC 14, HP 37, ATK 2 (+1 per Storm Hag) shock +6 (1d10) + 1 per hag and 1 lightning, MV near (Levitate,) S +4, D +2, C +1, I +2, W +3, Ch +3, AL C, LV 8 

Sister Power. For each sister in the trio add +4 hp, +1 attack +1 Shock damage, and 1d8 Lightning Damage. Storm Hags never move beyond Close proximity to one another and attack as a group.

Storm Born. Immune to Electricity.

Shock: Instead of claws or teeth, these hags employ short range jolts of electricity.

Lightning Blast. One target within near DC 15 DEX or 3d8 Damage (add 1d8 per Hag in the trio or coven.)