Tree Spirit
A tree spirit is a player with an Elder Spirit Tree Core. They function the same as any normal player, however, they cannot leave their tree or it will wither away, taking the players life with it. The default configuration allows they player 10 seconds to return to their tree before it dies.
The mechanics are based on The Tree Spirit Challenge.
If the core is destroyed by another method (including the tree spirit breaking it) this will register as a death of the tree and kill the tree spirit.
Planting and growing an Elder Spirit Tree Sapling will spawn a Tree Spirit Core for the player. The sapling grows much faster than those in vanilla so the sapling should be planted with the expectation of the player becoming a tree spirit.
A tree spirit must be directly next to their core in any direction. Tree spirits can expand their tree with Spirit Tree Logs originating from a position around the core. The logs can form a block chain to the core allowing the tree spirit to branch out.
Logs have the same safe radius as the core, meaning the easiest method for branching out is to create a floor with them. When in a staircase, an alternative is to line the wall with a diagonal root of logs.
An alternative to using the branching method is to create a safe room with a Room Sealer. The room allows the player the freedom to stray away from log/core blocks without the tree dying.
Getting to other dimension takes more planning as a tree spirit. Entering another dimension will distance the tree spirit from their tree. A Dimension Spirit Tree Core, created with a Dimension Spirit Tree Sapling, connects to the tree spirits main core from any dimension acting as the main core for that dimension. Given that the time to set up a dimension core may be too short in some situations, there is a Life Extender that extends the time a tree spirit may be away from their tree.