Jubokko Tree

In Demon Realm there exists a yōkai tree, known as the Jubokko (樹木子, "tree child"), that sustains itself on the life force and energy of other living beings. To this end, the Jubokko sends out large seed-like objects into the its surroundings. These seeds will seek out hosts of significant life force, and assimilate themselves within the hosts body. Once there, the Jubokko seeds begin to siphon the energy from their hosts, feeding it remotely to the tree. In most cases, this results in the death of the host, as the seed will take the entirety of their energy to feed the Jubokko before moving on. However, if the host can overcome the will of the Jubokko tree, they can gain mastery over the seed, and in the process gain the Seigan.