From Breaking Worlds
Spirits of Wood are energetic, curious, and idealistic, though they may be prone to anger. They take a particular interest in newness and growth, but generally have the patience to watch things take root and develop.
Using Wood spells or binding a spirit of Wood grants powers associated with other living things. Healing and communication are common Wood effects.
Principles and relationships
The key attribute of Wood is growth. It is the element of birth, childhood, and the springtime. It always seeks to grow and expand - often in the form of healing, but also through the spread of ideas and information. These traits can be turned to darker ends in the form of relentless expansionism.
Wood is allied with Water, with which it shares the attribute of curiosity. However, spirits of Wood are likely to see Water as too serious and secretive.
Wood is also allied with Fire, with which it shares the attribute of change. However, spirits of Wood dislike the destructive aspects of Fire.
Wood is opposed to Earth. The ideals of individual growth and change that underpin Wood are completely at odds with the stability and communitarianism of Earth.
Wood is also opposed to Metal. Where Wood wishes to expand and learn, Metal seeks to confine and reduce.
Inspirations for characters aligned with Wood could be lively enthusiasts like Luna Lovegood (from Harry Potter) or Steven Universe, mentor figures like Baloo (from The Jungle Book and adaptations), or idealistic leaders like Carrot Ironfoundersson (from the Discworld).
Villains aligned with Wood are likely to be aggressive and expansionistic - the Borg (from Star Trek) are a good example, as are the historical proponents of settler colonialism.