Aura
An aura is a region or area where the effects of one of the Realms of Power are more or less clearly noticeable, and is always aligned to one of these Realms. The strength of an aura is measured by its level (1-10), a higher level indicating a stronger aura. Level zero stands for the absence of an aura, which means that no mythical effect is in place, and that the local area is as mundane as it can be; at the opposite extreme, an aura score of 10 is as strong as possible and still be connected to the mundane realm: you are at the very gateway of another, un-Earthly, realm.
If auras of different Realms overlap, usually only the strongest and most dominant aura is noticeable.
Effects
Auras always affect mythical effects and creatures, including the magical effects evoked by magi. While effects and creatures that are aligned with the same Realm as the present aura are supported, those of other Realms are usually impeded. Effects aligned to other Realms may not function within a contrarily aligned aura; likewise, creatures aligned to an other Realm may not be able to enter such an aura at all, depending on their Might score and the level of the aura, respectively.