Troy, initially known as Mysterious invader when first encountered, is a villainous entity who acts as the true final boss of Just Kill Me.
Original FormWhen he first appears, his name appears as "Mysterious invader: ????". Troy is a hulking entity, far larger than the Demon God. He has a completely black body and a white face. Four differently shaped eyes adorn his face, and constantly roll back and forth in their sockets. When damaged, Troy temporarily becomes a mass of black tendrils and his eyes bulge out at the player. When he is defeated, he lets out an ear-piercing screech instead of the Demon God's usual meow. The reward for killing him is more than 1aa coins.
Troy is again seen in this form when encountered as the final boss.
Infection FormIn this form, Troy has taken over the body of the Demon God's copies. He appears similar to the Demon God, but stands in stiff, unnatural poses. In later versions of this form, eyes have begun to sprout from the infected Demon God's chest. In Just Kill Me 3, Troy's final form looks like the Demon God, but with some noticeable, and terrifying differences: Instead of his usual, constantly smiling face, Troy has a face composed of three vertical eyes with black sclerae and glowing white pupils circled by red. He also has three normally positioned eyes with the same features as the ones on his face, which lie on his torso in a top-to-bottom arrangement. Above the top eye on his torso, Troy has a large black hole in his chest, with three glowing white circles with red rings, which rotate around within the hole. His eyes constantly move back and forth, with the eyes on his face widening and contracting repeatedly. When he is defeated, Troy let's out a ear-piercing scream, followed by him distorting and stretching while changing colors finished with an explosion.
Virus FormTroy takes on a form consisting of only his face, which is only seen when the last Demon God uses his remaining strength to force the virus out of his body in Just Kill Me.
After it is revealed that human beings were not actually created by the god Demiurge, but rather by his counterpart the Destroyer, the true purpose of Troy is shown. Troy was created by Demiurge to infect the Demon God, who, after being killed by the infection, would pass it on to all of Humanity, leading to a world wide extinction event.
- Troy's name may be a reference to the Battle of Troy, in which the Trojan Horse was used to infiltrate the city of Troy, much in the same way that Troy infiltrates the body of the Demon God.
- In Just Kill Me, all Tama do the same damage to Troy as well as the two corrupted Demon Gods regardless of the current level of the player's basic damage.