Metamorphosis

The first of the sorceries, a gift to the first of the intelligent races. It was originally used by the Ðōnujulaeab, who mastered it; it was the secondary sorcery of the Zerɮudōju, and the tertiary sorcery of the ɮudōju.
This sorcery is considered as old as the planet itself- which is constantly changing, land moving, life evolving. Some believe it was the first true manifestation of this power that Awoke the ðōnujulaeab. However it came about, the ðōnujulaeab considered it their gift to use to help the world.
This ability was used to help heal plants in the early days before animals. Healing in an intrinsic piece of metamorphosis. After the evolution of animals, the ðōnujulaeab also would heal them in their wanderings. They also worked to help slowly evolve animals into larger and different shapes. Evolution in this world happened so rapidly because of sorcerous influence. They also used their sorcery to Awaken the zerɮudōju when the ðōnujulaeab considered them ready for intelligence.

Effect

Metamorphosis is also called the sorcery of the self. It involves changing oneself into new forms; it could somewhat accurately be called shape-shifting. But metamorphosis goes beyond just the physical. One can use it to change their body, yes, but also their mind or their very heart. Those are more difficult.
The ways this sorcery can be used are many. Much knowledge of it was lost when the ðōnujulaeab returned to Sleep. But some stories remain, and many zerɮudōju still keep memories of the great powers of their mentors.
Its earliest known uses were that of Awakening the ðōnujulaeab and allowing them to walk. They changed their bodies so they could uproot themselves and travel the land. They would then change their forms into different regular trees they saw about them, ensuring they were closer to the nature of the area. They also changed in part their hearts and in part their bodies; they made themselves the first of the long lived. The oldest living ðōnujulaeab is now over 300,000 years old.
They were able to give themselves more animal-like appendages when animals truly evolved, finding them greatly helpful in tending the land. True legs they had already discovered, but arms, eyes, ears; those were all welcome additions.
They considered meditation to be a kind of metamorphosis. Remaining physically still while the mind wanders and changes course was to them sorcery. They had never had minds aware enough to do that before.

Side/Secondary Effects

Their practice of sorcery enabled them to live longer, though they used their power purposefully to extend their lifespans. It is also rumoured that they were the first to summon a shadow semblance.
The overuse of metamorphosis, especially within a short time, can put great strain on whatever is being changed. The user will find themselves feeling weak and tired as though they just worked physically for a long time. In ðōnujulaeab, they can begin to feel dry and their boughs brittle. Whatever part of something was being changed can reject new changes if made too drastically or too quickly. It can also cause a thing to collapse. For example, one trying to change and shape their mind too quickly can suddenly find their mind splitting ever so slightly.

Manifestation

There is nothing visible unless the metamorphosis is physical. There is much evidence of this in The Metamorphosis of a ɮudō. People would suddenly find themselves with claws, scales, horns, barkskin, or over 4 meters tall. They might be able to understand the speech of deer, or feel the urge to migrate with the birds.

Source

Their powers flowed from the world itself, often credited to the shadow and their own inner strength.