The NB
The NB combines the powers of Knight and Bishop.For example, from e4 this piece can go to d5, and if d5 is empty can go to c6, and if empty b7, and likewise a8; or from d5 to f5, g6, h7; or to f3, g2, h1, d3, c2, b1; or (using its Knight power) can go from e4 to d5, f6, g5, g3, f2, d2, c3, or c5.
Of course this piece is weaker than the FIDE Queen, but it is stronger than you might think. The fact that it moves in 12 different directions helps quite a bit.
The Pawnless endgame of K plus NB versus King is a forced checkmate: with the WK on g6 and the Black King on g8, bring the NB to e7 with check and then play (NB)e7-f6 mate.
The NB is a weak Queen. It is viciously stronger than a Rook, and although it is weaker than a Queen, the NB is clearly in the same class as the Queen.