Rampulus is an outer-dimensional monster that, thanks to the return of Cor Hydrae, was able to slip into the Trail of Souls.
Known as a "mind parasite", it feeds on the despair of other living beings. Aboard the Phantom Goldoba, it creates illusions of Lyude's deceased associates to lure him in, including his siblings, foster nurse, commanding officer, and victims of Operation Sweep.
The species is very similar in appearance to two other outer-dimensional species, Sikri and Gnosis.