Aether
Absorption of the elements for physical enhancement
Where Weaving manipulates an element outside the Weaver's body, Reaping works from within. A Reaper absorbs their element directly, holding it in an internal reserve rather than acting on it externally. That reserve is referred to as a Well and fuels a Reaper's abilities, shaping their own body or a specific trait.
Reapers draw on the element stored in their Well and the size of it is not tied to their bodily condition. A Reaper has a natural limitation on capacity which can be expanded like a muscle, but with a hard cap that is individual to each Reaper. Exceeding that ceiling can result in an extremely dangerous condition known as Overflow. The larger the reserve, the stronger a Reaper is and if given unlimited access and quick absorption they can continuously Reap indefinitely. However, the way a Reaper modify their can potentially damage the body itself. If a Solar Reaper stores up fire and uses it to modify their body to either withstand heat, transform sections of their bodies into living flames, or similar things their body might overheat from the strain if maintained for too long. In a worst-case scenario the body itself might melt from within, leading to instant death.
The way a Reaper absorb their element is individual to each one. Some ingest their element or graft them into their skin. Others do it through respiration or osmosis (touching it and the body absorbs it through the skin). It can also be a forced absorption where an element, e.g. lightning, hits hard enough so the body can either absorb or take the impact. A forced absorption is the most dangerous way for Reapers to do it, but often also gives the most powerful abilities.
Reaping's expression varies by affinity, and even within one. Some Nature Reapers can reshape their entire body through full shapeshifting, while other forms of Reaping might sharpen a single trait rather than the whole form. What every Reaper shares is the underlying act, an element absorbed and held, not simply commanded externally.
No individual can both Weave and Reap. Every person able to touch the Aether is one or the other, a divide as fundamental to how they wield their affinity as the affinity itself.