Self-propelled gun (SPG)

After witnessing their train mates turn into monsters, Levi accepted Marina's proposal to form a marriage of flesh. She thought that, as the marriage was a new being altogether, it would technically be outside of the festival's roster. However, this was not the case, and the new being got moonscorched anyway. Soon accepting its fate, the creature travelled to the tower, ready to challenge anyone approaching.

The SPG is not Marina + Levi, it's the moonscorched form of an entirely new being, for whom Marina and Levi are akin to past lives. The SPG understands what its purpose was, and that it failed. It understands and accepts its fate, that it's now just another monster to be hunted down by any normal human left in the festival. So it just wants to get it all over with, refusing any dialogue and shooting on sight. Nevertheless, it enjoys the thrill of battle and takes pleasure in using its powers. It embraces its ephemeral existence as a death battle machine. Contrary to appearance, the SPG has only one actual head. The SPG's brain is housed inside Marina's head. The entire Weeping Scope half is basically just meat, a glorified extra limb with a third eye that can zoom in and out.

In "Fear & Hunger" mode, make sure you have both Marina and Levi as party members when you save to Day 3 Night. Thus, the official SPG will be awaiting at the tower. Otherwise, the SPG is always available as a repeatable battle in one of the locked cells within the church basement. This is in order to allow SPG to be fought in Maso mode as well, given that the official SPG isn't possible to spawn in Maso. Only the official SPG drops the two related souls and a body that can be looted. The official SPG also replaces the Cocoon and Weeping Scope fights, naturally.