Short Castling

Long Castling

Movement of Pieces

Internet chess
Movement of the new pieces

The RookKnight has movement of Rook or Knight,
as long as, just like in traditional chess,
the position allows it, it can move along the row or column.
It is noteworthy that the Bishop Knight can be a Bishop, that acts in Black or White diagonals since the movement of Knight allows that change.
In the same way the RookKnight, when acting as a Knight,
you can change columns and rows.
It is necessary to clarify that Bishop Knight can only choose to be
Knight or Bishop on each player's turn.
The Rook Knight only assumes the character of Rook or Horse,
when the player deems it necessary.

Bishop Knight

Rook Knight

The two Optional Moves
by play of
Bishop Knight - Rook Knight