By chosing a direction for the first turn you create a chiral piece, and a quite messy one of its kind since it mixes wide and narrow moves. The only other rotationally symmetric nightriders are the two possible "half quintessences" by chosing lateral (3L) or diagonal (3D) continuations only. I still have them in my mind to stage them in some game to be designed.
Of course, there are also potential combination pieces, the Boa used by problemists is only one of them.
By chosing a direction for the first turn you create a chiral piece, and a quite messy one of its kind since it mixes wide and narrow moves. The only other rotationally symmetric nightriders are the two possible "half quintessences" by chosing lateral (3L) or diagonal (3D) continuations only. I still have them in my mind to stage them in some game to be designed.
Of course, there are also potential combination pieces, the Boa used by problemists is only one of them.