Super Smash Brothers - Sheik is not feeling it.

He was standing right next to her. That sword should of hit.

OBJECTION!
The Monado cannot cut sentient life from the Bionis ! It's safe to assume that Hylians are vulnerable to it. Additionally the red frame of the Monado is still a solid object that should have hit Sheik for 1% even if he/she were immune!
Logical conclusion: Sheik is a Telethia and used Soul Read to dodge Shulk's attack.