The Nightrider moves as follows: it moves as a knight, but can continue to move in the same direction with additional knight moves, provided that the `leaping points' are all empty.
King c5; Nightrider e5; Knight c3, d1; Pawn b6, d4.
King a1; Knight c2, c8; Bishop d5; Pawn a6, c4, e6.
Mate in two moves.
White moves: 1. Nightrider e5 - d7 (tempo). Now, while this move doesn't threatens mate, every move of black discloses an opportunity for white to give mate - in all cases by moving his king and giving a discovered mate with the nightrider.
Note that there are eight different moves for the white king: each is used as a mating move, and after each move of black, white has exactly one possible way to give mate.