Aldemotte said: Well if you look at the second panel you see Yuugi stopping the sword with her hand from attempting to cut her horn. So it may still be up for grabs.
But judging from the sound effect, the first panel clearly indicates a solid "clink" sound (Gin) of hard objects clashing. Then there's the SFX for grabbing (Gashi) which appears right after in the second panel. So it would seem like Yuugi grabbed the sword after stopping it with her horn.
I just noticed on my third run through of this doujin, but Yuugi seems to switch her fingers randomly when laying into Reimu in the fourth panel. In the third panel she's readying her ring and pinky finger, but it's her middle and forefinger that slams into Reimu's gut.