Here are the main characters of this fanfic.
Gintama main character:
Sakata Gintoki: An odd jobber that was been used to be an rebel and a samurai after the war between Amanto he retires as a person who lives in Otose's place as an apartment, he is a person that is seriously an idiot towards public and hardly loves sweets and couldn't handle without having any in at least 1 day.
Overlord main characters:
Ainz Ooal Gown: 1 of the strongest and top players of YGGDRASIL, before he was an undead he was an human that lives in an generation where nature was all been destroyed due to point where his humanity gets into the level of evolving products and technologies into a higher level, but for some unexplainable reason he was been isekai as an overpowered overlord of death which he proclaims himself as the grim reaper, the god of death, the sorcerers king, the almighty supreme being but he is loosening his human personality ever since the day he became an undead but he still cares for other, currently he is focusing on a goal which is taking over the world, replacing heroes and let the whole live world know that the true hero is him only him.
Albedo: She is the overseer and also the general of the floor guardians, she played the role as M towards Ainz whenever she had times with him, she is a person that brought a heavy hatred and underestimating personalities towards humans and the living beings that are not in Nazarick, although she could be out of control some times due to the point for jealously towards the womans that she misunderstood is attracting her beloved overlord but she is still a bit serious towards the floor guardians.
Shaltear Bloodfallen: The level 1 – 3 floor guardian, she is an true vampire and also known as the bloody Valkyrie, Shaltear like Albedo she's the second person who plays the role M towards Ainz and also Albedo's rival from getting Ainz to love her a vampire that easily gets out of control whenever she is in the state of berserk and blood frenzy.
Cocytus: The level 5 floor guardian a frost giant insect that brings huge and large respects towards the peoples that has great warrior spirits, he is mastery at sword fighting and also a floor guardian that manages the divine weapons of the supreme beings, he is skillful as swords and other weapons like Gintoki although he takes things seriously then Gintoki, unlike Gin he never slack off or do anything that is related to Gin's hobbies.
Aura: The level 6 floor guardian looks like a boy but the truth is that this elf is an girl, she is a person that always feels excited for all sorts of daily days and missions from her overlord, although her hobbies are bad towards wild animals in the forest, she loves to skin all of them all.
Mare: Another level 6 floor guardian unlike the sister this elf brings the opposite of all sorts of things related to the sister, the elf is a boy, he wears girl and female clothes including the hairstyle and the actions, he is sensitive, always nervous and very shy towards everyone which is why somebody misunderstood that he was an girl instead of a boy which just makes him feels even more nervous than before, although his spells of manipulating earth elementals could not be underestimated due to the point because the spells of earth manipulation is on an level that an advanced to a high level wizard and mage couldn't obtain or mastered, he loves reading books and quite peaceful places.