The Bell Tower location says, I believe, "after defenders are declared kneel and discard Bell Tower, cannot be saved, to remove all characters from the current Power challange".

What happens to the characters? When they are removed are they Kneeling or Standing? Do you get to attack again with the same characters or are the original characters kneeling and then do you get to attack and defend again, with different characters?

Please help.

They are simply removed from the challenge. If they had to kneel to participate in the challenge, they stay knelt. If they didn't have to kneel to participate in the challenge, they stay standing. They are free to participate in other challenges as long as they are able to fulfill the costs of doing so (i.e. kneeling).

An example of a location that would stand a character and remove it from a challenge is Toll Gate.

So Bell Tower basically can end a challenge and keep any kneeling characters involved in that challenge from doing anything for the rest of the challenge phase, unless you can put them in Standing position from some other effect?

Can you initiate another Power challenge? Or by Bell Tower ending the 1st Power challenge does that count for your one Power challenge per phase?

Jack54 said:

Yes, the characters were knelt so they stay knelt. You initiated a power challenge even if Bell Tower ended it. You will need another effect to initiate another challenge. If you could use the kneeling characters again and initiate another power challenge, Bell Tower would kind of be a waste of a card!