Arch Cut (斬り払い, Kiriharai; lit. Cutting Sweep) is one of Strider Hiryu's command normals.
Hiryu lunges slightly forward while slicing his sword downwards. This move is similar to the Ame-No-Murakumo, except it lacks the blue special effects and the added properties of Ame-No-Murakumo.
This was originally Hiryu's Heavy Kick animation, but the button layout of Ultimate causes this move to be a command normal. It gains ground-bounce properties and a bit more startup time as a trade-off.
Hiryu also has a similar motion used for his sweep/crouching Heavy Kick and his original jumping Heavy Kick (which is instead his j.S in Ultimate), where he does an outward clearing slash.