Two new skill gem ideas: Mental Deflation and Spirit Burst

Various builds stack various stats, such as damage, life, ES, armor. To these there is not really any uber limit, at which it would not be benificial to stack even more. One stat that difer in this is mana regen. If we ignore MoM, you only need enough mana regen for your skills to be activated. After this point, stacking more mana regen does not help you at all. This is the source of insiration for these two skill gems, that would make it worth while, to stack as much mana regen as possible.

Mental Deflation
Spell, AoE, Duration, Damage over time, (some element or chaos)

This spell channels your mana to damage enemies in a cone in front of you. While channeling, you gain a mana degen, that increases in magnitude over time. The damage is proportional to the mana used, so the longer you channel, the more damage you do. When you begin to channel faster than your mana can regen, the degen will contenue to rise, but your damage will be limmited by your mana regen.

The spell is tagged duration, because it takes some time to get from one level og mana degen to another. This makes reduced duration very helpfull, as it would both reduce the time you need to channel to get a lot of damage.

The nature of this spell also makes stacking mana usage usefull as well.

Spirit Burst
Spell, AoE, (some element or chaos)
This skill cannot leech

This spell functions a lot like Vaal RF. You hit the button, your mana goes to zero, and enemies in a cone in front of you takes damage proportional to the mana you lost on activation. This means that stacking a lot of mana, and stacking ways to regain your mana will be very usefull.