When he goes after Sephiroth, Cloud is impaled through the chest with masamune. He then somehow manages to grab the blade without losing his fingers and lever Sephiroth off the platform. Even if this was possible due to his enhancements from Jenova cells, and Sephiroth didn't notice his imminent demise because he was too absorbed with his "mother", it still doesn't explain Tifa. We clearly see her get sliced across the chest and thrown across the reactor by the sword. How were they savable when Shinra showed up?
Also, when Tseng is mortally wounded in the Temple of the Ancients, how does he get out/survive? It's all kind of confusing.