Tsennu are a sub-species of Julth. They are capable of joining with sapient hosts, gifting them with special abilities. In some cases, the Tsennu will control the host's mind.
Like all Julth, Tsennu resemble glowing beams of energy. When they have a host, the host will cast a glowing aura around itself.
Tsennu enter universes through Dimensional Rifts through the Crossverse. Once they find a sapient being, they will enter its body. The host will be given many powers, including force fields, laser beams, and sometimes FTL abilities. With FTL, hosts can travel from planet to planet near instantaneously.