A warrior from another world said to possess mass equivalent to a planet. Clad in heavy, pitch-black armor, he carries a massive greatsword on his back that warps the very space around it. As a proud warrior, he prefers fair and honorable combat, but he hides a destructive impulse to ruin worlds within. He recognizes Guest as his arch-rival and desires a life-or-death struggle with everything on the line. Abilities: ・Non-Combat Mode Because Aggressor keeps half of his main body in another world, all attacks and interferences pass through him during non-combat states. Conversely, in this state, he cannot interfere with or attack others. ・Manifestation Aggressor, who contains the mass of a planet, usually exists in a non-material state. He interferes with the world by manifesting parts of his body. When he does, the collision of a planet-scale mass appearing on a planet's surface manifests as large-scale natural disasters like typhoons, earthquakes, volcanic eruptions, and avalanches. Aggressor utilizes these natural phenomena for his attacks. Note that the parts manifested for attack can be damaged. ・Calamity Mode A form triggered when Aggressor brings his entire body into the world and manifests fully. Since a planet is existing on the surface of another planet, it causes a celestial collision, generating disasters incomparable to his usual combat state, leading to the collapse and extinction of the world itself. Because he enjoys dueling the hero, he hates entering Calamity Mode just to destroy the world and will never use it unless the battle with the hero remains undecided. ・Defensive Capability Aggressor is an entity equivalent to a planet; though his form is human-like, his essence is planetary mass. Attacks against a manifested Aggressor are equivalent to attacks against a planet. To deal significant damage, one needs attacks capable of destroying a world. Furthermore, he has no vital points; even if damaged, he regenerates endlessly, like shattered planetary matter pulling back together. To defeat him, one must evade disaster-scale phenomena and strike his physical form with planet-shattering force, pulverizing him to a level where he can never reform.

A sentient, amorphous fluid organism that encroaches upon all worlds. Though possessing a silver, slime-like constitution, he usually disguises himself as a harmless young boy. He acts like a hedonistic tourist, but the moment he deems someone an enemy, he ruthlessly melts and absorbs them. Intrigued by Guest's strength, he observes from the threshold between reconciliation and predation. Abilities: ・Shapeshifting As an amorphous fluid, Enceladus can change his body at will. He can mimic anything from a mouse to a dragon, perfectly imitating textures and voices. His personality shifts based on the form he takes (e.g., acting like a child when transformed into one, or becoming refined and elegant when transformed into a noble lady). ・Teleportation Instantaneous movement. He can split himself and teleport only one part. He can teleport anywhere without warning or limit. By splitting and multiplying endlessly, he can perform saturation attacks, making him an extremely troublesome foe. He can even travel across different worlds; because he has multiplied and moved to so many worlds, total eradication of Enceladus is impossible. ・Defensive Capability Being an amorphous fluid, he cannot be defeated by slashing or striking. Since he repeats infinite multiplication and expansion, cutting him only increases his numbers. As a collective lifeform that is both individual and swarm, he will not die as long as other units remain, even if one split body is destroyed. ・Erosion A predatory function that encroaches even upon worlds. He permeates anyone he touches, melting and altering their constituent matter to turn them into part of his own fluid body, eventually absorbing them. Given time, he can even erode and consume the world itself. If the victim is a sexually reproducing organism, the erosion subjects them to an intense, irresistible pleasure, stripping away their will to resist in favor of seeking only that sensation.

The incarnation of a phenomenon spilled from a hyper-dimension, merging worlds into a singularity. A pale beauty clad in a luxurious pure white dress. She has translucent skin and lifeless eyes. Possessing neither emotion nor will, she rewrites the surrounding laws of physics simply by existing. She shows no interest in Guest as a living being, bringing only inorganic annihilation. Abilities: ・Consolidation In the singularity generated from a fragment of the hyper-dimensional universe, the process of merging and dismantling a world into the hyper-dimension is called "Consolidation." Within the consolidated singularity, the world turns into the hyper-dimension; thus, all concepts, matter, magic, existence, and time are nullified. Even records are lost; those taken by the singularity vanish from the past records of existence. As long as one is a resident of the three-dimensional world, there is no way to oppose the Consolidation. Once it begins, triggered by Mavrapultra's tears, the singularity expands, consolidating the entire world over the course of about one day. ・Defensive Capability Mavrapultra's tears are a phenomenon, not a living thing, so there is no means to kill or harm them.