Since Karin can smell chakra: what are you HCs for the characters' chakra smelling/feeling like.
Aaah, I've been waiting for this question... Expect a long answer from me, as always... šš
First, I must say that the smell Karin senses goes far beyond the "smell of roses" or "smell of sweat", as you said. She can sense whether a person is good or bad, and whether or not they are lying, exactly as some people believe animals do when they smell us. But, as we know, she has proven to have a much greater sensitivity than animals or any power in any Village.
Still, we want to know the real smell too, lol. So I'll try to give a description of both - the physical smell and the smell of their "nature".
Chakra Smell: Aside from the time when Sasuke was going through a bad phase, his smell is as pure as his personality. If we take into account what Karin herself says, Sasuke's smell is "dark and cold". This may seem like a bad thing, but I think it's the feeling of being in a cabin on a snowy night. The cold is comforting, and unlike the heat of a sunny day that burns your eyes, you feel an almost hypnotic desire to watch the snow falling, and sometimes, an deadly impulse to stand under it, even though it will hurt you at some point.
Physical Smell: Sasuke doesn't seem to be very vain, but he certainly doesn't allow himself to get dirty to the point of smelling. As someone who is always traveling, he must smell like the grass and bushes he passes by, and he also has his own soap and shampoo (which he prefers to have a non-perfumed scent, but still give off a fresh and pleasant aroma), which he takes with him to bathe in when he stops at a Ryokan on a regular basis, or if he has no choice, in some secluded stream.
Chakra Smell: Jugo's chakra essence must be the best of all. Besides being a good person who seeks peace when he is not under the curse mark, he never lies. There are some scenes where Jugo holds Karin in his arms or touches her in some way, and even though she is so "skittish", she never seems to mind. I always compare Jugo to a big teddy bear that you can hug, vent and cry for hours on his shoulder, and even though his expression remains the same and he will not give you an answer to your problems, just the fact that he is there already makes you feel good. He smells like "home".
Physical Smell: In Shippuden, he smelled really bad. Jugo didn't seem to have been taught how to bathe, since he probably didn't have anyone to take care of him since childhood. He didn't cut his hair and almost never changed his clothes. He smelled like sweat, blood, and of course, animals. In Boruto, Jugo smells minimally good because Suigetsu and Karin taught him to take better care of his hygiene. He cuts his hair regularly and takes a bath (at least every three days...). He still wears the same curtain he wore in Shippuden, and I'm sure he lets the birds do their business on him and doesn't care... So you better enjoy it while he smells like soap right after a bath, because when he goes to the forest, he'll smell bad again.
Chakra Smell: The worst smell on Team Taka. Suigetsu was a cold-blooded killer practically since birth, there was no compassion or kindness in his personality, and I don't doubt that he would easily lie to deceive an enemy (or for less). His smell was like being caught in freezing rain after a bad day. However, we saw his personality change along with Team Taka. He became a reliable companion and learned that the lives of others matter. In Boruto, even though he still has his acidic personality, he is clearly not as cold-blooded as he was in his teens. He smells like... Being caught in a drizzle after a happy day. It's still annoying from one perspective, but from another, it makes your day even better and makes you want to stop and let the thin layer of water accumulate on your face and give you that cold, funny feeling.
Physical smell: I don't think Suigetsu smells like anything... His sweat shouldn't have a very strong smell and the scent of any soap or perfume shouldn't stick to his skin for long, thanks to his anatomy. Some people think that his water ability is something that can be activated manually since it's listed as a jutsu in the Databook, but based on his statements and the times he was caught off guard and liquefied, he's literally made of water 24 hours a day. Odorless and tasteless.
Chakra Smell: A very strong smell, just like her personality, for sure... Due to her difficult past, she ended up creating a thick shell around herself, so she was not honest about her feelings, most of the time, in addition to being unnecessarily ignorant with people, as if she wanted to protect herself in advance. Imagine that you went to a bookstore, and there is that delicious smell of new books everywhere and you could spend hours there, but there is that side separated by a chain where there is a warning for sensitive people not to approach... You feel an immense urge to go in there, wanting to take the risk to see what you might find, but at the same time, the fear of getting a lecture and being thrown out forever makes you unsure about going any further. In Boruto, the same thing. But I think you are so intrigued with all the other interesting areas that the bookstore has that you don't care about checking that forbidden area. Maybe one day, who knows.
Physical Smell: The best of all. Karin is extremely vain. Not only does she love perfumes and has a collection of different scents to match her mood of the day, but she also uses a product for each area of her body, knows what kind of cream to use for each season and doesn't let cheap shampoo touch her hair. Her skin is very soft, and even when she goes on long trips, she *needs* to stop and take a shower at least once a day. If she can't, she uses perfume to not smell so bad. This also keeps the scent of her chakra disguised from potential enemies.
Bonus: Orochimaru smells like "Danger, move away immediately and carefully or you will be bitten". But he physically smells really good and is almost as vain as Karin. Mitsuki smells like a baby because he IS SO BABY. And Log smells like cigarettes, obviously... His chakra smell shouldn't be too noticeable. I feel like he smells like sitting in a leather chair and reading a good book.