Polnareff is attacked and possessed by Anubis, a Stand without a Master.
I had forgotten just how many of the fights in Stardust Crusaders focus on Polnareff. It makes sense in retrospect, since he’s the only one in the main group with a close-combat Stand other than Jotaro, and there’s always some amount of fun to be had in making people slug it out (or in this case, fence it out). There’s not really anywhere for Polnareff’s character to go other than the “haha, he’s a doofus!” route, and while that’s not necessarily bad, it just feels like a bit of a missed opportunity, especially since his climactic confrontation with the Hanged Man took place so early in the story.
As Jotaro says, Anubis is the first enemy Stand in a while that doesn’t rely on cheap gimmicks to win, unless you count selective cutting or the ability to “remember” its opponent’s moves (hell, or the ability to possess people) as gimmicks. It’s still a Stand, after all. In proper shonen-battle-manga fashion, there are some pretty good twists throughout the fight, including Polnareff’s totally-had-it-the-whole-time-guys sword gun and Silver Chariot dual-wielding against Star Platinum. The latter is a fairly iconic moment, being included in the OP (with a second rapier instead of Anubis, to avoid spoilers) and as a playable variant of Polnareff in the old Capcom fighting game alongside both Chaka and Khan.
Rather than the action, however, the highlight of the past two episodes has to be Anubis’s amazing freak-out upon being defeated. It’s common in JoJo for the villain of the week to not just be beaten, but humiliated, and Araki delivers on this spectacularly. David Production could have played yakety sax over the entire sequence of Anubis flying through the air and mentally flailing to avoid drowning in the Nile, and it wouldn’t have been out of place. It’s a bit of whiplash after what was a life-and-death battle between friends only minutes ago, but that’s basically par for JoJo; it wouldn’t be the same without dramatic fights and stupid antics in equal measure. And speaking of stupid antics, I am so looking forward to the next enemy Stand-user…