Ankh

At first impressions, Ankh comes out as an asshole utterly indifferent to the fates of those around him. This is not too far from the mark. As a personified being born of human avarice, he only has a few concerns: his Core medals, that make up his full body; finding Cell medals, which serve as a way for him to gather strength; maintaining a steady stream of popsicles; and above all else, his own survival, even at the expense of random humans. Since he is the physical embodiment of human avarice, what he wants and desires comes above anyone else's. He is also adept at twisting people's greed in a way that is useful to him. Even without monsters being concerned.

If one is ever able to get closer to him, they might find a few other sides to him. First, he is a schemer and a planner. He never makes a move that's uncalculated, and will usually keep them to himself, even counting on the indignant reactions of his allies for success. Once he threw the guy he'd given the OOO power to off of a building into Tokyo Bay in order to keep a rival Greed's Core Medals away from him. No one but him knew that was coming, and he just laughed smugly to himself at the top of the building when his plan was a success, despite the protestations of another of his allies. However, they don't always go perfectly, and he doesn't react well when this happens. He throws a tantrum and curses a red streak. He doesn't often consider the possibility of being outflanked.

Secondly, even if he tries to look like he doesn't have any care for your average human, he does grow attached before too long. He has a very odd way of showing it, sometimes. At first he'll present it as a way that benefits him, but after a good long while he'd admit to the feelings and act more openly on them. Certainly not without some dramatic catalyst to remind him what's really important, anyway.

He also grew quite attached to the things that humans took for granted, like five senses. His fixation on popsicles (or ice cream bars in general) came about because that was the first human food he'd tried after taking control of Shingo's body. The sweet coldness was such a new thing to him that it was basically all he ever considered eating, until Shingo's sister strongarmed him (literally) into eating other real food for the sake of her brother's body. He still freaks out if served chicken, though.

He adjusted quite easily to life in modern Tokyo, despite not having existed around humans for 800 years. This was assisted by accessing Shingo's own memories about things like where he'd stored an iPhone he'd secretly bought but he also picked up on how to pass in modern society just through observation. Before they created human-looking bodies of their own, he was able to keep tabs on his fellow Greeed by watching the twitter feed of people talking about seeing weirdo monsters. He didn't seem to experience a whole lot of culture shock, except where the fragility of his own body proved inconvenient. In the end, he does help save the Earth from being consumed by the power of avarice, even at the cost of his own life.

Sample:

What the hell was this creature doing here? He'd locked all the doors, and all the windows. And yet this ... thing was here. Napping, or perhaps merely waiting on the sofa. He glanced around and saw its fur on a few other pieces of furniture. How long had it been here?

May as well take this threat head-on. Ankh was far from a coward. He turned to face it and crossed his arms over his chest. “Hey! What's the big idea?”

The cat still slept soundly, and didn't acknowledge his words at all.

“Oh, you think you can ignore me, huh?” He stepped around the coffee table and picked up the cat by the scruff of its neck. He held it up at arm's length and looked intently into its yellow eyes. The cat meowed in protest, and wriggled around a little.

“What the hell are you up to here, huh?” He demanded again. He jostled the animal around a little.

But when he did, a jangling caught his attention. The cat was wearing a collar with a bell on it. And there were tags. He reached to turn the tag so he could read it. According to the tag, its name was Chiyoko. His eye twitched. The tag also had Ankh's address on it.

He abruptly let go of the cat who dropped safely back onto the couch. Chiyoko looked up at Ankh and rowled at him again.

Of all the insufferable, unnecessary, absolutely inane things... Ankh just stared at the cat as it hopped off the couch. She started rubbing against his pant legs. She even started to purr. She seemed to have forgiven him for the abrupt awakening. Or was luring him into a false sense of security. No female of any species could be trusted.

He turned from her and charged to the main stairwell of the house. “Whoever is responsible for this furry bastard in my house needs to get down here and fix this!”