SO if you cast Vi ult on black shield she takes 0 dmg even though its physical. is this intended because she didn't get cc'd so thus forth you ult doesn't hit her? or is this just an over sight?

Hm, sounds like an oversight. It should still deal it's damage, just not CC her.

It's probably because the damage is dealt when Vi slams the target down, rather than when she knocks them into the air, and the Black Shield prevents the skill from even connecting in the first place. She never actually reaches the moment when damage is inflicted.

Dumb, yeah, but it makes 'sense'.

It is intended because the Ulti doesn't get to happen; the shield cancels the skill. Save thing happens with nocturne and sivir and banshee veil; there's another thread about it, it is just part of the mechanic

I am sorry but if vi Q can hurt targets with black shield on then vi ult HAS to do dmg at least.