[Exxy]

While Void being its own, unstoppable element is interesting, it's not something that would eat away at the user right out of the gate, since Void Poisoning is a consequence for using too much Void. I don't think we should jump to add Void as an element just yet.

On the side, if I were to implement Void Poisoning, it would look something like this:

Void Poisoning is, initially, nothing more than a hidden value with no real effect. However, if the character uses skills or spells that would involve unsafe use of the Void (I.e. Blink, Dark Shield, using Black Wind skills without wearing Heavy Armor), this value gets a small increase. It will also increase if the character is a target of said skills/spells, but on a lesser scale. Abstaining from anything that would increase the hidden value for a while will allow 'natural recovery' to start, providing a slow decrease to VP's hidden value, to a minimum of 0. This is the only method that can lower the hidden value when VP is inactive.

Once the hidden value reaches 100, Void Poisoning will be added to the character's wounds, alongside another value that we'll call 'LV'. LV starts at 1, and whenever the user would perform an action that adds points towards VP's hidden value, that action will instead give a very solid chance (75~80%) to increase Void Poisoning's LV by 1. While Void Poisoning is active, the character's maximum HP receives a (5*LV)% penalty, to a maximum of -100% Max. HP. (This penalty cannot reduce maximum HP below 1)

Obviously, this wound cannot be handled by most means. In order to cure Void Poisoning, its 'hidden value' must be reduced to 0. Unlike its inactive state, Void Poisoning will not see a 'natural recovery' while active. There would be a few methods for other characters to provide treatment for a Void Poisoned character:

(NOTE: Each treatment can only be applied to a Void Poisoned character once per IC day)

-Specialized Aid (Requires Rank 10 First Aid, 20+ WIL, Physical Stamina > 50%, VP LV < 5) A hands-on approach that has a 50% chance to reduce VP's hidden value by 5~10, consuming (VP decrease*5)% physical stamina in the process.
-Melurify (Requires Rank 10 Solmancy, 30+ WIL, 40+ FAI, Mental Stamina > 50%, VP LV < 10) A special type of Mercana that will reduce VP's hidden value by 10 without fail, consuming 50% mental stamina in the process.
-Plague Gamble (Requires 75+ Amiras Loyalty, Both Staminas > 50% each, VP LV < 18) A call for the aid of Amiras, who will, on an entirely random chance, either reduce VP's hidden value by 25% of its current value (min. 5), or increase VP LV by 5. Either way, this consumes 50% from both types of stamina.
-Mercala's Cleansing (GM only) A blessing from the goddess herself, which reduces VP's hidden value to 0.

On the other hand, Void Poisoning as a wound may be something to be placed behind a 'hardcore'/'true roleplay' switch, given how it's presented via lore.

This is easily the most agreeable post I've seen on the subject.

About the only thing I would have to add is the person who activates the voidgate or is the caster of such related skills to be the one who takes the recoil damage (essentially for being the catalyst, without their presence there wouldn't be any exposure to begin with) and for the people who are exposed to such through second-hand means to take less of a value increase (at least mechanically) than the causer.