The Norse are all cultivators by at least some definitions, gaining power via Ordstirr, a measure of their glory and reputation. Universal powers that come with Ordstirr and experience include being physically and, to some degree, mentally superhuman. The three fundamental principles of their cultivation are "Power Demands Sacrifice", "All Men Die" and "Memory Is Forever".
Being physically superhuman, for the Norse, involves being inhumanly strong and fast and so on, but also notably includes them receiving physical damage and just keeping going...just about any adult Norseman can receive an apparently fatal wound and just walk it off and eventually heal with how many fatal wounds they can take varying from Norseman to Norseman. As they grow in power they also develop low-level shapeshifting abilities, allowing them to boost their senses, strength, speed, and so on even further...they can keep a few of these alterations active at any one time, and swap them out outside of combat (at very high levels, they can do these swaps in combat as well). Norsewomen are generally worse at this than Norsemen (seldom reaching the shapeshifting levels), but that's cultural rather than actually enforced by the cultivation system. These abilities all fall under Hamr, the Norse word for 'body'.
Being mentally superhuman notably does not include superhumanly smart. It's more a matter of superhuman sensory perception, willpower, and the speed at which they think. Still very useful of course. At higher levels, they gain the ability to alloy together multiple Kunna (see below), or other abilities, creating cool meldings of those things. At extremely high levels they also gain Rewrites, the ability to impose their will upon reality and very occasionally (a few times per season) temporarily just change a detail about how their magic or abilities work. Norsemen are normally worse at this than Norsewomen, but again that's just a cultural standard, not enforced by anything. These abilities all fall under Hugr, the Norse word for 'mind'.
All Norsemen also have a Fated Day, a day when they are doomed by fate to die. No injury, no matter how severe, that they receive before that day can really kill them in a metaphysical sense. Which means that, any time they die prior to that, a seeress can shove their soul back in their body if the body is even vaguely intact, and if the body is not intact, a shapecrafter can make a new one out of any piece of the body, even a lock of hair. Most Norse people thus keep a lock of hair somewhere hidden in their house just in case. There are some ways around this, such as 'soul killing' attacks (a bit of a misnomer, the soul eventually recovers, but not in time to get brought back like this), or formal duels that call upon the Gods (the Gods make sure the loser is not brought back). Of course, as an Outlaw, Barki is unlikely to receive any of this treatment...his bodily death may well be his last one, even if it is not yet his Fated Day.
In addition to just baseline superhuman abilities and not dying, the Norse have what they refer to as 'Tricks'. These would likely be called 'Techniques' in a more traditional xianxia, and can do most of the stuff you'd expect of that, allowing flashier superhuman feats like leaping attacks, deadly palm-strikes, and so on, but also social and mental feats or superhuman prowess at farming, all at the cost of Ordstirr when used. Many Tricks have very prosaic names and get reinvented enough by different people that these names are not standardized. Example names include things like Sowing Sense (a farming Trick) and Leaping Cleave (an attack Trick).