"Challenges: Kneel The Shadow Tower to add 2 to your total STR during any challenge in which you control at least 1 participating Night's Watch character."

Is this a lasting effect or does it only affect one challenge?

Only the challenge during which you kneel it.

Any official clarification about this one?

Because the text sure is confusing.

Any official clarification about this one?

Because the text sure is confusing.

Kneel The Shadow Tower to add 2 to your total STR during any challenge

maybe it's just me, but I don't find this confusing. Unless you find a way to stand this location back up during the challenges phase, since it doesn't end that sentence with "till the end of the phase," it's kind of an unwritten limit of it only working during the challenge it was knelt.

I'd have written it as " Challenges: If you control a participating character with the Night's Watch trait, kneel The Shadow Tower to add 2 to your total STR for the current challenge." (or something with "until the end of the challenge" that makes it obvious it lasts only for the current challenge.

I'd have written it as " Challenges: If you control a participating character with the Night's Watch trait, kneel The Shadow Tower to add 2 to your total STR for the current challenge." (or something with "until the end of the challenge" that makes it obvious it lasts only for the current challenge.

Very true. That would have prevented people over-thinking it, but I, personally, think it should work the way it is currently worded if people just take it at face value.