Just noticed this bug today as I started playing samurai again, not sure if it has always been there or if it is new, but you cannot shoot the Amateresu with it aimed within 3 tiles of a wall. This is especially noticeable in stone guards fight, when trying to use the ability. Also in Oryx castle when trying to get extra damage to break walls and fight brutes. Note that the other samurai abilities don’t have this issue, so I am pretty certain it is a bug as opposed to a feature (if it is a feature, why?)…
Edit: note that there is some “sweet spot” where you can fire right at the edge of the wall, but within 3 tiles away you cannot (unless this is only happening to me for some reason)…
Video of showing this in vault: