Nooo...Energy shield blows all the goats in the yard.
Chain Lightning is what they use. When equipped with the right gear, they can do ALOT of damage. For example:
My NovaNecro would put on his Lightning Gear for PK:
4Topaz Shield
4Ort Armor
Ort Blackhorns
Wizardspike
Thundergods
My necro has about 900 life.
That gear, vs FoH pallies, is basically unbeateable. Even with Conviction maxed out at 125 or 150%, my resist is still 95. But, the lightning sorc with the right gear and one good hit can easily drop my life by 400+ or more.