The Host is an instantiation of Alibii in the form of a floating heart. Valor encounters the host within the Red Plains, where she tries to impede him by reviving the dead Sequels littered throughout the area.
Construction of the Red Code Mirror is in progress... You must not compromise the memory buffers.
Recursive operation detected. Your consciousness is now entering your consciousness. The singularity.
The Host is very similar to the Transient Heart, both in appearance and function.