So I took a bit of a look into this OP and it seems the Rider vs Saber part Shirai mentioned is the last 2 cuts in post #68454.

As for this upload, I'm not sure what's the source for Abe doing this but while it's likely he did the first cut, the genga(ex1 ex2) for the second cut imo looks notably different than his usual work(including his other work on this OP ex3 ex4) particularly the layer notation and the smears. So if he in fact did that part it was probably only layout/rough genga.