User blog comment:Arad1376/Moonlight Butterfly/@comment-3492791-20140708151821/@comment-2093249-20140722053500

Yes it is a bug, unfortunately the boss's collision frame will get stuck into a blank section under the bridge if it goes flys too low. However this usually happens at the beginning of the fight as it comes off the side of the tower.

It can also happen if Beatrice fires certain spells off at the boss while its perched on the side charging its blast.

@Arad1376 - If you enter the gardens and place the summon sign after the small pond, that is close enough to keep the fog gate from closing and baring your friend.