When standing in a specialised Glyph of Dominion with Tendrils of the Invoker node selected, casting Lightning Blast consumes mana on every chain instead of adding to the mana cost. This results in losing all mana in a few casts.
The mana cost from Tendrils of the Invoker is correctly added to the cast of Lightning Blast only when casting without Convergence.
Steps to reproduce on Runemaster Mage:
- Specialise in Glyph of Dominion
- Put 3 points into Tendrils of the Invoker
- Specialise into Lightning Blast
- Put a point into Convergence
- Cast Glyph of Dominion
- Cast Lightning Blast while standing in Glyph of Dominion
- Observe Mana getting drained on each chain of Lightning Blast
How I found out about this:
I made a build with Dragorath’s Claw trying to maximise the Lightning Blast procs from Frost Claw combined with Glyph of Dominion. I noticed that I can sustain non-stop casting for a long time until I put down Glyph of Dominion. It made me think that it’s Lightning Blast destroying my mana pool until I looked further into it and realised that Lightning Blast has a low mana cost, even with Tendrils of the Invoker. Testing the skill interactions I found that Lightning Blast continues to drain mana after I cast it while standing in Glyph of Dominion. Furthermore, the mana cost created by Glyph of Dominion with Convergence is not affected by Foot of the Mountain boots, which makes sense because it’s draining mana that’s not part of the cost of Lightning Blast.