[Kairos]

If I understand what you're asking, not quite. To apply a bonus or limitation to a power, I use a gizmo, which is sort of a child object attached to the power. That lets me use a form to apply Bonus and Limitation picks to my power pick. The eval script defined on the Power thing will look at which Bonuses and Limitations picks I've applied to the Invisibility pick (in the case of Invisibility, I would use a "custom" Bonus for the # of senses to which the power makes you invisible), then adjust the BaseCost tag appropriately.