Sebastian Moran does not smoke. He never has in his life. Aside from an old family struggle with the bottle, Sebastian keeps himself in perfect health. He eats well, works out, and he doesn't point anything in his body that would destroy his finely tuned instrument. A sniper's body is as much his weapon as his gun or his brains. Sebastian would never let any of his guns fall into disrepair. He'd never let his mind get any less sharp. He'd never let his body be anything less than in perfect health.
When the sun rises Sebastian wakes up for a run, before returning for a quick shower and breakfast that is the proper balance of nutrients, carbs, and proteins for his particular body and his particular lifestyle. He's just as likely to spend time working with his punching bag as he is working with the complex mathematics problems he plays with in his spare time. It's a bit of an obsession with Sebastian: staying alive.
That's how Sebastian knows that Jim is suicidal even before he puts a bullet in his brain. The smell of smoke in their flat comes from Jim, not Sebastian. The junk food is Jim's. The Soda is Jim's. The boxes of stupidly sugary cereal are Jim's. There beer in the fridge is Jim's taunt to Sebastian, but neither of them really will touch it. When Sebastian drinks all he wants is whiskey and vodka, and quality be damned. When Jim drinks all he wants is whiskey and vodka, but quality couldn't be more important.
"If I'm going to ruin my perception it's not going to be for shitty vodka," Jim complained before when Sebastian would drag him in off the streets after one of Jim's alcohol induced benders. "Cheap vodka is boooooring. It's so dull. It doesn't even burn in a way that's interesting, it just vaguely burns and it doesn't even taste like drinking embalming fluid. It's just dull. Awful, boring, boring, boring. No, it needs to taste like a morgue and set my throat and teeth on fire and slip right down to my belly where nothing else matters for that one glorious minute."
Jim was chattier drunk than when he was sober, but mostly he talked about alcohol. Jim always went off on his own to drink. The only time Sebastian ever found him was when Jim had reached that point of so drunk that he knew he needed help, but not so drunk that he'd just pass the hell out and let anyone do anything to his body. Blackout-drunk Jim scared Sebastian more than any other Jim.
Jim wasn't supposed to be seen that out of control. Jim didn't like not knowing exactly what he'd done. Sebastian was the only one in the organization who could see Jim like that, but Sebastian also couldn't be around alcohol without relapsing. When Jim ran off on his own (which he did with great frequency) and Sebastian found out later that Jim had drunk himself right out of memories, Sebastian would get scared. He'd rather clean up Jim's vomit then to accidentally see dark bite marks that Sebastian was sure caused some kind of ghost of shame in Jim's eyes.
Luckily this hadn't happen often. More than Jim wanted to die, he didn't like being out of control. Like Sherlock Holmes, Jim had his little array of drug use, but only until Jim's body started to acclimate to the affects and then Jim would drop the habit. He wanted it to be interesting. He didn't want to be out of control.
Jim wasn't addicted to anything, but he liked the idea of inhaling death. Sebastian had once witnessed Jim try to inhale mustard gas before Sebastian dragged a mask over his face. Sebastian's main job was always to keep Jim from doing irreparable harm to himself, but that wasn't a job one could do forever. Sebastian got Jim to a point where he could die and still win, and Sebastian honestly felt like that was success.
After Jim's death and after the funeral that Sebastian still wasn't 100% sure he should have attended Sebastian found himself drawn more and more to the six pack of beer in the refrigerator. Somehow beer had never been his drink. It disgusted a bit. He sat down on the sofa with an open can a sipped it as daintily as Jim would sip a cosmo. He drank the whole pack and bought another but he did it a lot slower than he'd drink a bottle of vodka. He didn't bother with the vodka.
One day Sebastian found a pack of cigarettes in the back of his sock drawer. Jim had to have put it there, though Sebastian couldn't fathom why. It was a pack of Lucky Strikes. Sebastian didn't know why Jim seemed to prefer them. All he'd ever get out of Jim when asked about it was Jim saying "LSMFT" and then cackling like a loon. The pack Seb found in his sock drawer were from America. The giant "Smoking Kills" label was nowhere to be seen.
Sebastian found another pack of cigarettes among his things one day, Ява, a Russian brand. This one was stashed away in Sebastian's gun rack. He found more cigarette hiding in his case of bullets. The next day he found a single Lucky Strike tucked in his work bench.
"Fucking lunatic," Sebastian mused, finding his lighter (the one he carried for Jim). He lit the end and held it in his fingers until it burned down to the filter and Sebastian put it out of his work bench. Maybe he just liked to watch it burn, or maybe the burn reminded him of Jim and his rants on what it meant to drink good vodka. Either way, he felt better having lit the thing.
A week later Seb found a pack of British Lucky Strikes hidden in the sugar (where Jim knew damn sure Sebastian would hardly ever touch). Without even putting thoughts into mental words, Sebastian lit the end and pressed the filter to his lips. He inhaled, but choked it back up again. Sebastian was reminded of the couple of times he'd been too close to a fire when camping as a boy, and the times he'd gotten caught in house fires for various reason. There was nothing pleasant about the burn in this throat. He put the cigarette out in the sugar, dropped the lid back on the bowl and returned it to itself place. The pack of cigarettes he left on the counter where no one would touch them.
Three days later, Sebastian smoked half a cigarette from the Russian pack. He put it out on the coffee table and stalked out to the balcony where he proceeded to choke as if he could expel poison from his lungs that way. That afternoon he finished one from the American pack and put it out on the balcony. He didn't choke that time.
It became a routine with him: a beer and two cigarettes a day until he ran out of beer (which he didn't buy more of) and cigarettes (which he did, though those he hid in his sock drawer to replace the pack he'd taken). The next time business called him to Russia he bought a pack of Ява and put it in the sugar bowl. The next time business called him to Russia he bought a pack of Lucky Strikes and left it at his work bench.
Sometimes when the day had been particularly hard Sebastian would go to one of those places and pull out a cigarette. He'd light it on the balcony and just watch it burn. It burnt the tobacco. It burnt his finger tips when he wasn't careful, his tongue and lungs if he was. Only Jim needed a sniper as good as Sebastian, and somehow Sebastian couldn't imagine that and occasional cigarette every couple of months would do more than knock a year or two off his life. After all, what was a year or two of life in the face of an eternity of boredom.