{riders of galvony} could I {cloudshift} and call another creature type that my humans would have protection from? So let's say when I summon him I call vampire. Next turn could I {cloudshift} and call zombie? thus giving humans protection from both? The card does not state as long as it remains on the battlefield.
No, flickering (either through {Cloudshift} or {Restoration Angel}) {Riders of Gavony} does not let you stack the different protection from creature type.
Rider's ability is a static effect, and your choice is tied to it. When flickered, the Rider is then considered a different object and will require a new creature type to choose from.
Cloudshiftong riders is great for "updating" protection to deal with new threats. But when you do, you will certainly lose its previously called protection, as riders are now a new object.
If you want multiple protections, you'll have to use multiple riders. {cackling counterpart} and white populate, anyone?
Thanks guys, someone tried doing that to me and I didn't know.