Infinite Mana Tempest, Mana Tempest drain

Mana Tempest can be sustained indefinitely using Demon Form.
Steps to Reproduce:

1. Cast Mana Tempest
2. Go into or exit Demon Form.
3. Don't leave the zone created by Mana Tempest

When transforming, the mana cost per second of Mana Tempest is still increased,
but not actually applied.


Not sure if a bug but confusing / inconsistent.
The description of mana tempest states that 30% of the mana spend while inside is added to the cost per second. This includes the cost per second itself, which means that the cost constantly rises after the first spell cast.
However, the amount the cost goes up is different when mana is full. As long as the mana pool is not full, the cost rises slowly, regardless of the cost (by about 1 mana per second). When it is not full, it rises by about 10 per second.
Probably due to Mana Regen but it still feels like a bug.

There is a bit more in to mana tempest actually.

Skill itself had some wording issues. Mana tempest actually improve spells that have no mana cost, but in description it says differently.

Mana drain is currently bugged, in a way which prevent the mana drain rising at all. Can't replicate it properly, but on my character I had 3k mana and around 250 mana regen. While trying different levels of mana tempest I find out that mana drain starts increasing only if base mana drain is between 22-28. While I keep base mana drain value below 22 I can improve those ice shards and freely cast them with 50+ extra lightning damage.