Enchanted Quiver

To get the additional value for the shielding-prevention effect, you need to have a face-up arrow in your arsenal before Enchanted Quiver’s activated ability resolves. If you do, prevent the next 2 arcane damage that would be dealt to you instead of just 1.

This is a shielding-prevention effect that prevents the next 1 arcane damage (or 2 arcane damage total if you have a face-up arrow in arsenal) that would be dealt to your hero. This can be over separate events of damage (i.e. 1 arcane damage, then 1 arcane damage).