Yeah, as I said, he was fodderized. It's most likely that we didn't see the entire fight though, but he has been really hyped up. A LOT of people in Naruto would survive an attack like that. As far as him defending or dodging it, he still fought Tobirama, one of the strongest shinobis ever, so I'm willing to accept that Tobirama beat him anyways, just not that easy.Well, it was nice to see, however...Izuna had a mangekyou, at least, this has been told to us.
Thats why I find it so srange to see he died of a swordslash, since he could likely use susanoo to defend against it.