That's what I thought, but it makes sense if the body was indeed Madara's.
It's hard to think of a body that would startle him more. Realistically speaking, it should be someone that he'd recognise too. For example, if he's never seen the Sage of the Six Paths, then showing him some random body wouldn't phase him.
If it's not Isuzu-chan Mii~
One thing that is bugging me is why the fascination with Sasuke now? Oro previously wanted Sasuke for his Sharingan, as he couldn't get it from Itachi. If the Sharingan is all that is needed, surely Madara could supply a couple of eyes instead of giving him Sasuke?
1. I don't think Kabuto knows Madara has a bunch of Sharinga. And 2. I don't think Madara has any intention of giving Sasuke to Kabuto. Or giving him any spare Sharingan. He's not going to give Orochimaru II his clans Bloodline ability.
Also, Kabuto's reason for wanting Sasuke may be simple revenge. The guy DID kill his master.
Upon further inspection, I suppose he could be Obito if you assume that is scaring we see. He does share Kakashi's powers (affinity for lightning and similar Sharingan ability), as well as having a matching eye. Toss that in with the 'that won't work on me' he suggested to Kakashi and maybe it is Obito.
Still, it doesn't fit his character at all. We saw very little of him but still, I would be very surprised if that were the case.
Was this the ep where Sasuke was retrieved by Tobi after he defeated Itachi and they're in some hideout?
Now... we can click as warriors... button to button, it is the basis of all internet.
Only a fool trusts his life to a virus.
It does seems like a stretch. For all we know, lightning techniques have always been blue. There's no real way for us to tell if that's just the animation department's take on his teleportation/projection technique.
If it's not Isuzu-chan Mii~
Well, that was him using his teleportation technique, which since then we've seen has nothing to do with lightning.
I remember thinking he had some kind of Lightning Step at the time also, but when I checked the manga, there's no lightning in that scene, so I'm guessing it's just the animation team embellishing.