Shield Stun

[Jazriel]

Does this vary by character? It seems a lot of the time that when I do a d-air with Kirby my opponents shield grab me before I can grab them (obviously I'm z-canceling). Yet whenever I shield an aerial I always get grabbed after. When I play as jiggs though I grab before other people can.

 

[Wenbobular]

Yes it's dependent, but you shouldn't get shield grabbed by anyone because Zcancelling is instantaneous.
And it varies by the moves, so yes it varies by character. Captain Falcon has pretty ridiculous shieldstuns on all his aerials, which you can't say the same for like...drills.

 

[ant-d]

About Z-cancelling and shield grabbing

If Kirby were to D-air a shielding Fox, Kirby will have 5 frames head start to initiate a grab before fox can shield grab. If you are 5 frames too slow after the Z-cancel then the opponent can shield grab successfully.