He can remove bending this is proven in the last airbender when aang learns that before they bent the elements they bent energy this means that he is permanently blocking the flow of chi so in theory you could possibly call it chi blocking but on a much more extravagant scale.

The giant turtle-thing that taught Aang how to energybend said that only people with a pure heart can energybend. Amon definitely doesn't have a pure heart

Dang you got me there
nice point thumb for you

If that wos true then Korra is a freak of nature since she can also bend all elements

So he's not taking it away, he's just permanately blocking it?

well, that might be the case. Maybe he doesnt "remove" it, but instead he clogs the chackras (spelling ftw?) and prevents bending somehow?