Moral light balance

The moral light or moral shadow of a being determines their elemental and mental alignment.

Explanation
Moral light is not linked to standard Light elemental power in a way that would make them more susceptible to its influences, nor is it linked to Shadow in such a manner. Moral light is, however, linked to the mentality that a being of light would typically be part of, namely the more positive emotions, such as joy, nobility, and aspiration, while the standard mentality of a being of shadow would be linked to malice, hatred, and greed. This is not, however, a guiding function of their mind; a being of light can still have malevolent intent, while a being of shadow can still perform meritorious actions. However, if a being is completely consumed by a certain element, the emotions of their personality will begin matching the emotions carried by the element, unless the being possesses extreme willpower or prior knowledge of how to stop the change.

Elemental Structure
Any naturally formed being contains at least a small amount of both light and shadow inside of them. The amount of light or shadow carried by each element affects the element itself, but has next to no changes on the personality of its wielder, save the changes that the element itself provides, i.e. the hotheadedness of a Ta-Matoran. However, the amount of moral light and shadow does differ among each element; for the eight main elemental Matoran types, Kra-Matoran obviously have the most shadow, followed by Ta-Matoran, Onu-Matoran, Le-Matoran, Ko-Matoran, then Po-Matoran. Ga-Matoran have the second-highest amount of natural light out of the basic Matoran types, bested obviously by the Av-Matoran. If the amount of natural light is permanently changed, the body will eventually come to accept the new element and change to fit it, though the being will likely still be able to control the element that they once possessed.

Shadow Leeches
Developed by Makuta Mutran, Shadow Leeches unnaturally drain out a being’s moral light and places a psychic shield around them that keeps it from returning, causing it to instead fill with shadow. As the being’s mind and body does not see this as a permanent alteration, the entity drained by the Shadow Leech will not switch elements to match the new combination, but will retain their original element, as well as gaining a power over shadow.

However, if the change is complete, it will produce an affect similar to if the being would willingly have banished their internal light, leaving them solely capable of manipulating shadow and with their bodies keeping none of their moral light. Matoran changed in this way are referred to as Shadow Matoran, instead of the official Kra-Matoran name used for natural Matoran of shadow. Though they have effectively changed their element, the mental shield created by the Shadow Leech can still be broken, which will return them to their original state

Yet, beings who willingly banish their moral shadow or moral light, such as Umbra or the Makuta species, respectively, do not produce a damageable mental shield; they can only bring back the lost element through extreme effort and meditation. A similar process to the one used to create Shadow Matoran can forcefully drain all of the light from a being; the only piece of equipment known to be capable of doing this is the Kanohi Avsa. The resultant beings are incredibly similar to their Shadow counterparts in that their original element disappears and that a mental shield forms to keep away their moral shadow. The Matoran created this way are referred to as Light Matoran, much as the Shadow Leeches made Shadow Matoran. Any being with all of its light sapped out of it, whether willingly or unwillingly, will die when an attempt is made to remove the shadow, and vice versa. Even if they do not perish due to a massive effort of will, they will still be, at the best, shambling, unthinking creatures neither alive nor dead