Turtles All the Way Down
Loki is a dead man in a still-moving (if not necessarily living) body. The vast proportion of his current existence is made up loitering around the most vile dens of vice in all of Furrabia, generally accompanied by a large hookah from which he constantly smokes a stream of the powerful (and highly illegal) narcotic drug known as nár'sofa (roughly 'corpse-sleep'). The quantities and lengths of time during which Loki consumes the substance would likely kill anyone else, however Loki's strange metabolism means he only gets a vague sense of disassociation from it at best. Nevertheless, Loki pursues his habit with a near-manic intensity. It's not immediately obvious what he is attempting to use the drug to escape...
While in this intoxicated state, Loki's personality tends to be lethargic, laconic and sensual. He regards the world through a cynical, but amicable, addled haze and is rarely seen without a bitter, rueful grin. Very occasionally, he can be seen in the company of slaves and escorts; he has a tendency towards 'shy' males of average appearance, and for all intents and purposes he seems to simply desire the warmth and company. He will occasionally engage these individuals in conversation, from which it can be ascertained that Loki considers himself to be the last of a long-forgotten pantheon of gods, stripped by time of his family, identity and (almost) all of his powers. He is utterly nihilistic, and though he obviously deplores the institutions he currently finds himself a de facto resident of, he apparently cannot bring himself to actually do anything about it.
Loki's shattered defeatism extends into other areas as well. The rarity of nár'sofa, and the fact that Loki is, indeed, highly addicted to it, means that he must constantly acquire a steady stream of money in order to fund his stupor. His primary means of doing so is to take advantage of his unique physical talents and hire himself out as an assassin, master-thief and generally shady jack-of-all trades to whomever happens to be desperate enough to pay him. In an almost perverse kind of self-punishment, Loki will take any job, no matter how reprehensible or dangerous.
When 'on the job', either through hired work or rare personal initiative, Loki's personality changes almost alarmingly. When not in a narcotic stupor, he is wise-cracking, egotistical, self-assured and alarmingly kind-hearted; an almost clichéd Trickster archetype. He is as creative as he is destructive (often both in any one action), and abhors stagnation and hubris.
No matter what state he is currently in, Loki seems to have an irritating habit of never calling anyone by their actual name; 'kid' or some variation is common, or else a poetically offensive description.
When not intoxicated, Loki is a chain smoker; producing long, thin cigarettes from a thin silver case. He has a habit of lighting the cigarettes by simply sucking on them; this apparent control over fire can be extended to other uses, though Loki often appears to express frustration over the sheer difficulty of conjuring up fire from nothing (as if this weren't always the case). He also has an occasional tendency to display empathic abilities, especially to individuals with whom he has had close or extended contact. Again, this limitation seems to frustrate him enormously. Despite his apparent limited 'magical' abilities, Loki almost always appears to prefer physical confrontation or diplomacy over 'flashy magic battles'; he holds a great deal of scorn for the majority of so-called magic users, belittling their abilities as mere conjuring tricks. If Loki has any extended magical abilities, however, he does well to hide them. In confrontations especially he fights viciously with tooth and nail, and has an alarming habit of consuming the flesh of his foes (he occasionally can be heard referring to himself as an 'Eater'). He also possesses two ornate, curved short-swords roughly the length of his forearm, as well as a heavy, black gun carved with glowing runes. He can apparently materialize all these weapons out of thin air; though does not seem to possess this ability with any other object. His weapons are all obviously magical in nature, which means that they have a tendency to misfire and malfunction. When forced to use his gun, Loki is a comically terrible shot.