@Ciaran Yeah, there's a lot of potential with Jasmine's power. It's why I'm glad that one of her limits is that she can't directly affect the Awakened, she'd be able to instant gib the bad guys too easily otherwise. Though, while she theoretically can steal and give any amount of momentum, it isn't always practical to do so. She can only affect complex objects as a whole, which is why her mountain presence upgrade lets her target specific bits. Because of this, the inside of whatever she's targeting is still going (though I'm gonna say there are special exceptions so I can cover my bases if need be), meaning blood is still pumping within an organic body, passengers within a moving vehicle are subject to whiplash and everything else that would occur if it suddenly stopped, and vehicles would technically have all their functions still operating.
So basically, it would cause some serious destruction to steal momentum from a car, let alone from a train. If Jasmine were a little more amoral, it possibly wouldn't be a problem for her, but if she knew what the consequences were for doing something like that she'd likely refuse unless it was a desperate situation. The safest way for her to use her Abstraction would be for small scale and/or simple things, though of course that's not going to get her a whole lot of momentum a lot of the time. Figuring out that sweet spot is going to be key for her in order for her to reach her max potential.
So basically, it would cause some serious destruction to steal momentum from a car, let alone from a train. If Jasmine were a little more amoral, it possibly wouldn't be a problem for her, but if she knew what the consequences were for doing something like that she'd likely refuse unless it was a desperate situation. The safest way for her to use her Abstraction would be for small scale and/or simple things, though of course that's not going to get her a whole lot of momentum a lot of the time. Figuring out that sweet spot is going to be key for her in order for her to reach her max potential.