Its quite a well known fact to the folks at Combat,Strategy and Gameplay that Necromancer is the strongest mage specialization in the game. You cannot die, you can dish out consistently high damage, you do not suffer from any game breaking bug and you can solo the game on Nightmare with all the Trials toggled on.
Just check these videos out:- https://www.youtube....lf_id=0&sort=dd
Knight Enchanter is in the middle. Spirit Blade and Fade Cloak are not as good as Walking Bomb and if you have Trials toggled on, you will have enemies with Barrier Breaker trait which effectively nullifies the Knight Enchanter's barrier generation.
Rift Mage is the weakest of the mage specialization because it relies purely on crowd control and weakness. Crowd Control does not work on the tough enemies and Rift Mage suffer from the Shock-Weakness bug.
Here are Rift Mage solo videos:- https://www.youtube....&view=0&sort=dd
You can and will notice that it takes a Rift Mage far longer to kill enemies on the highest difficulty with trials on compared to the Necromancer. So yeah, The Egghead's specialization is crappy compared to Dorian's specialization.
"But Pull of the Abyss is awesome !"
Pull of the Abyss does not work every time, unlike Walking Bomb which does work all the time on pretty much anything.
"Veilstrike...!"
Horror with Despair upgrade is far superior.
"What about Stonefist?"
Yeah, I will give you that one. Stonefist is the only super reliable effective spell the Rift Mage has.
"Rift Mage have mana regeneration !"
Necromancer has health regeneration and some mana regeneration. Extra mana can be gained using Fade Step with Energizing Step upgrade. Also, Rift Mage loses mana regeneration when fighting targets immune to Weakness or when the Shock-Weakness bug happen.
"What is this about Necromancer being immortal?"
Its because of Simulacrum and Death Siphon passives coupled with some enchantments. If you have a heal on hit or heal on kill enchantments and you die under Simulacrum, you will regain health back under spirit form because of the enchantment and when the Simulacrum runs out, you will be back up alive.
"What's this about a Walking Bomb exploit ?"
Walking Bomb takes time to hit a target. So if you are fast enough, you can fire 2 Walking Bombs in quick succession and it will only count as 65 mana. Or you can fire a Walking Bomb followed immediately with Energy Barrage and the Barrage is faster to hit on target so it will only count as 65 mana. Oh and if you use a Walking Bomb masterworks enchantment as a Necromancer, you can detonate the masterwork procced Walking Bomb to infect other targets.
Here is a video for that:- https://www.youtube....h?v=b6BXxlIyTQM
Point is, Necromancer > Rift Mage, especially for high difficulties with Trials, with KE being in the middle.