So, let's say, THEORETICALLY, someone decided to use A Test of Will to cancel the When Revealed effect of a Ranger of the North. Would the Ranger of the North be sent to the encounter discard pile, or would it just sit in the staging area forever?

Hmmmm it has an encounter back and is considered to be an encounter card and part of the encounter deck so I would assume it would either be sent to the encounter discard pile or because it is a player card with the encounter type it would potentially go into its owners discard pile?

I doubt it would stay in staging however.

I think the player that did that would be sent to the discard pile.

If you use A Test of Will to cancel the When Revealed effects on an enemy or a location, that card still goes into the staging area. Ranger of the North ought to be treated the same way.

Aha, the designers thought of my absurdity! From the Lost Realm's definition of the Encounter keyword:

• The "when revealed" effect on player cards with the encounter keyword cannot be canceled.

Moreover:

• If a player card with the encounter keyword leaves play, it is removed from the game. Do not place it in a player's discard pile or in the encounter deck discard pile.

Well, there goes my question about Born Aloft'ing a Ranger of the North...