Treyni/Abilities and Gear

Abilities
She can manipulate the magic power of nature. In particular, Dryads have the ability to transfer their consciousness to the trees and grass within the Forest of Jura. This allows her advanced informational gathering ability.

She has a teleportation skill that looks like Spatial Travel.

She has the ability to unify her own strength with the spirits she summons. It is unknown if this is an Extra Skill or a form of Magic. As of the events of Game's End she has demonstrated the ability to unify with an Elemental Lord of Wind, making her level of strength in that state rival an Awakened Demon Lord.

Rimuru also made her a Chaos Core to house her spirit just like Beretta's. Soon after Rimuru also makes her a body carved from the tree which served as her original body, giving her a unique, mobile body. Afterwards, he speculates her to be a sub demon lord in strength.