Either wait through an entire hustle animation, or catch a falling hustle knife by pressing hustle again as it contacts you, you should get Horizon after catching it.

Extra challenge, try to Horizon into another falling knife!

you can also just punch the knife to send it at people

引用自 kyriansmash：

you can also just punch the knife to send it at people

adding onto this, DI up/down affects the direction the knife flies in (left/right also affects it, but you may as well just use up/down, since left/right does nothing differently)