A vampire who lives in a dark castle on top of a hill.
Actually a 14-15 year old boy with a severe case of chunnibyou, his best friend 0144 has it as well. Both of them follow a strange and convoluted plot with each other, with 143 being Devil 0XXX, a mysterious vampire-like being who sucks out people's lifeforces when he touches them, along with being a master of the dark arts. He does not (read: in this make believe world) know that 144 is really Shota Hero, and at school is very friendly to him, while when battling Shota Hero becomes very sadistic and proud.
Is a spoopy vampire that goes bluh bluh
0143 is a chuunibyou who believes he has mystical satanic dark magic, and often goes on about murdering and enslaving everyone in The City. He goes by the alias “CITRON THUNDER” because he thinks it sounds cool as heck (even though it sounds more like the name of a car). In reality, he’s just a huge nerd that rarely leaves his house and is super bad at socializing. People think he’s just a weird otaku because he’s always wearing a weird vampire-esque outfit (he hates when people call him a vampire, and rather says his outfit is that of a dark lord's). When people tease him about it, he goes on to chant curses at them until they get weirded out and leave.
Although all the stuff he says about conquering everyone is just him tooting his horn and none of the curses he casts ever work, 0143 actually is some sort of demonic entity. He used to be the son of some important lord in Hell but he got kicked out to the human world for being really lame. Really lame meaning although he always threatened people, he was way too much of a pansy to actually hurt them (he also sucks at using his demon powers; the only thing he can actually do is levitate 3 feet off the ground and shadow-jump). So although he acts all tough he’s really a big softie that wants friends.
He is fairly tall (not over 6 feet) and is in his early twenties.
The ornament on his tie is actually a living thing, assigned to him by his Father to make sure he doesn't get into trouble in the mortal world.
0143 is a NEET that lives in the middle-class section of The City; because of his lack of income, his landlord 0135 is constantly getting on his case. Despite this, she lets it slide, as she is interested in his strange chuunibyou mindset.
0135 is kind of his only friend, and sometimes they go drinking and exchange bits about their lives.