The train... Hits him dead on, he'd be sent flying into the damn air and even crash into what's left of the roof, the only stopping him from going higher being a rafter that's still somehow standing. Despite that, he simply looks angry and slightly amused by the vast damage he's just been hit with.
"Hahaha! Oh man, that was actually a really good one kid! Damn if I wasn't expecting less of a fight here! Alright, little boy, play time is fucking over now you're dead!"
He rushes, even faster than normal as darkness flows around his right foot, he'd snicker and press down into the gash left by his blade. The black magic covering him taking the shape of razors along his foot, Chaos Tatsuya grinds them into Lowe's neck, he'd laugh and press in a bit harder while glaring down at the boy.
"I might look your age kid, but I know everything that other one does and then some! I've got all his skills, even more, power, and none of those stupid morals that are holding him back! And you dared to stand against me? Hah! I admire your balls, but I'm still gonna end ya for it!"
Finally, he'd raise his foot up once more, rather than tiny razors this time his magic shapes into a wicked looking cleaver blade going down from the middle of his shoe. He'd aim to send it flying straight downward, pushing the thing into the gash once again, and finally once his kick loses its force, he'd shoot the blade downward with magic, rushing it off his foot and sending it flying down with even more force to hopefully slice off Lowe's head entirely. Then, he'd turn to the audience of this little show with a grin on his face... Heh, he should be able to help Minato out here too actually.
"Good evening everyone! Did you enjoy tonight's showing? It was a pretty good duel if I say so myself! And all thanks to my nifty little power, not sure if anyone else can see it, but I've got a cute skill that's been letting me keep you bastards from getting involved. Anyways, please don't hold your applause!"
"Got a skill", hopefully their little minds will link him to the strings... He's not looking to keep the heat off himself, so if he can gather up the attacks Minato should be getting? All the better.