Find the probability of this aura.

If you actually calculate the expression in its title, the answer is 1 in i, the square root of negative one, so this aura is a math joke with no real drop chance. "Find the probability of this aura." is a developer-exclusive made for the developer Word, credited to 2word7, and it cannot be obtained from rolling. The Sol's RNG Wiki says it is not on the official Trello, which is why little is documented.

The title is a record of its own. The wiki says it has the longest name and the most words of any aura, is the only one with a period in the name, and is the only one with an image in the rarity slot instead of a number. The formula in that image is a floor-function expression that simplifies to the imaginary unit.

Visually it adds almost nothing: the only effect is the letter Sigma covering part of the face, similar to Undefined. The font is Ubuntu, and the wiki warns it can be extremely laggy and might crash a server, for reasons not explained. No biome, luck or event applies.