The Tree of Souls (Utraya Mokri) is a giant willow-like tree that's said to have the highest concentration of Eywa on the planet. The Tree of Souls can also create a one-way psionic link between two bodies, similar to how Avatars work. When Grace Augustine was injured, Jake brought her to the Na'vi and they attempted to save her by using the Tree of Souls to permanently transfer her mind to her Avatar body. Although Grace was too weak to make the transfer, Eywa absorbed her memories. At the end of the film Jake successfully transfers his mind into his Avatar, making it his true body forever.
I am jumping from morning to morning, I feel forced to enjoy this moments again and again. It's like an addiction and I think I can't do it on an other time. The light, the colours and the mood on dawning autumn are so inspiring!