@Florin: it would be surprising that this piece was not invented by the problemists. Interestingly looking at Alain Biénabe in the (French) Le Guide des échecs, I see the Red Cross. Like a Pyramid, it cannot take or be taken. It may move, but only to block a check on its K. For that it follows the shorter geometrical path. Invented by J.G.Ingram in 1934.
There is also the Blocker (J.Buchwald, 1934) an "inert" piece that may be transfered from the square where it stands to any other free square. It does not capture. It is not said if it can be captured, I would think not as it said "inert".
@Florin: it would be surprising that this piece was not invented by the problemists. Interestingly looking at Alain Biénabe in the (French) Le Guide des échecs, I see the Red Cross. Like a Pyramid, it cannot take or be taken. It may move, but only to block a check on its K. For that it follows the shorter geometrical path. Invented by J.G.Ingram in 1934.
There is also the Blocker (J.Buchwald, 1934) an "inert" piece that may be transfered from the square where it stands to any other free square. It does not capture. It is not said if it can be captured, I would think not as it said "inert".