Pull of the Abyss with the new damage toggle is amazing. First it's a quick 500% spirit damage. And as long as you put weakened on the enemies first, it's "free!!!!" Second it isn't exclusive to Lightning Cage. Get BOTH!
The "weaken" bug:
The weaken bug happens when you try to weaken a mob with "shocked" debuff on it. This will cause them to go to sleep instead of applying weaken. You have to wait for the shock debuff to disappear to then reapply weaken. All-in-all it wasn't really a problem with the new Fade Step toggle to get mana back.
The only enemy I know of that was immune to weaken completely, were Giants. And they were a pain. But other than that my Rift Mage playthrough (nightmare+trials) was fine.
I was using StarFlorge's Infinite Mana Rift Mage Build, which uses Lightning Cage and Chain Lightning. I did avoid lightning staves though, because Energy Barrage with a lightning staff would cause shock debuff. With Chain Lightning I was able to choose where and when I wanted the "asleep" debuff.
My basic kill sequence for trash went like this:
- Veilstrike (with weaken upgrade)
- Pull of the Abyss (with damage upgrade...now I have full mana)
- Lightning Cage
- Energy Barrage (with Energy Storm upgrade)...full mana again now
- Blizzard (if mana gets low, fade step through enemies..but it won't be until you apply shock debuff and reapply weaken)
- Chain Lightning (puts shock debuff on trash...avoid on single target)
- StoneFist (with weaken upgrade)
- Energy Barrage (causes nightmare on sleeping enemies)
By then most non-promoted trash are dead.
For bosses I swap the upgrade on Energy Barrage. If the boss has guard generation, I will swap the upgrade on stonefist too.
I uses that for most of the game with two exceptions. Gurd Harofsen in Jaws of Hakkon, I swapped to a boring Flame Array / Chilling Array. I find it really boring, but it is very effective. And I did the latter again to speed run through the fire room in Descent. It's better damage, but ridiculously boring IMHO.