Seems pretty complex for a single piece. The combination of double-move
AND leap, and the nuanced anti-trading restrictions, jumps out at me as
being an evolutionary design and not very elegant.
Kind of like FIDE pawns (with initial double-move, en passant,
promotion...). Pawns have been heavily tweaked over the years. That
probably makes FIDE a better game, but I would be reluctant to import all
of those quirks into a new game--especially one where pawns weren't a
major focus and/or where the target audience wasn't already familiar with
them. (And in fact, many casual chess players don't even know about en passant.)
