A strange set-up of superchess could be
Rook (R), Knight (N), Bishop (B), Emperor (Er), King (K), Counsellor (Cn), Veteran (V), Rook (R) on white's first row. With the same rules for castlingas in standards chess, you can castle with emperor and king. It is only possible to castle with both pieces, if the emperor and king castles "short", so
Castling with the emperor: Emperor to b1, Rook to c1 and with the king as usual.