Waelda take the form of giant sentient trees that possess very long life spans. They accumulate knowledge throughout their lifetimes. For this reason, the Waelda are often referred to as Sacred Trees or Holy Trees, despite just being a race of Enlightened Spirits. They are especially held in high regard by the residents of Kolima Village. Despite their longevity, Waelda can be injured and it take can years for them to heal from an injury. However, a quicker form of healing exists in the form of Hermes' Water, found at Mercury Lighthouse, which has been shown to restore even grave injuries within a short period of time. However, it is stated that if the Waelda die, the forest they are connected to will die as well.
Waelda appear to be sensitive to Psynergy. After the eruption of Mount Aleph, both Tret and Laurel were exposed to Psynergy Stones, which affected their emotions. Tret also gained the ability to turn people into trees, though he fell into an uncontrollable rage as a result.