Keys "s"=save "l"=load "b"=back once
L P D'Autremont, 1918. The "angel" is represented by a crowned knight, moves as Q+N. You cannot capture an angel if on the next move your own angel could be captured. An angel under attack by a non-royal enemy unit cannot check or capture the king. Pawns promote to angels only on the king's file.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!