Mensus is formed of Knowledge and boundaries. Where a thing is defined by its limits, Mensus stirs. The mere act of definition and assessment brings into being the concepts it finds most vital to its existence, and in turn it can bestow this knowledge to the minds of those whom seek it. Few beings know more true estimates than those enthralled by the Method of Measure.
A being that has become fully aware of their own measure suffers no negative consequences, however their actions are forever anticipated by Mensus in ways they cannot avoid. This phenomena has no perceptible impact on free will, only on consequence. Actions taken by such individuals will more often lead to other characters being measured - spreading the touch of the entity yet further.
Mensus manifests as Causality, Destiny, and Fate
The presence of Mensus bestows no mechanical benefit, but the world becomes more defined to those in its presence. What was once 'a stone' might become 'a one kilogram granite stone'. Awareness of definition extends to character knowledge - A character could become temporarily aware of their level, attribute ratings, or other statistics.