Though there are pieces that can move backwards, the strongest piece is 'Ramshead-Soldier' (Tai Shogi), which moves like a Bishop, but only in the forward directions.

There are 3 'themes' played out on the 9x9 and 8x8 boards, described as follows.
* 'Flying Snow' - plays with pieces that cannot move backwards.
* 'War on Pluto' - plays with the 'strongest' pieces.
* 'In the Nursery' - plays with the weakest pieces.

Gods on Pluto has 2 zrf's, 1 each for the 9x9 and 8x8 games. Mainline games are 'War on Pluto' and 'Flying Snow' on the 9x9 board. That being said, it is unclear to me which is better, the 9x9 or 8x8.

Piece Descriptions: In order of strength according to Zillions.

Ramshead-Soldier, Goose, IronGeneral, StoneGeneral and TileGeneral are from ancient Shogi variants. Xiang and Mao are from Chinese Chess. The others are pieces i have made up, or pieces that exist somewhere i have never seen :)

Ramshead-Soldier: slides diagonally forward any number of squares
IronGeneral: moves 1 square in the forward directions
TileGeneral: moves 1 square diagonally forward or directly backwards
SoldierHero: slides 1 or 2 squares diagonally forward
Goose: forward alfil, backward dabbaba
Mad-Dabbaba: forward dabbaba or slides 2 squares sideways
StoneGeneral : moves 1 square diagonally forward
Mad-Elephant: forward alfil
Mao: moves 1 square orthogonally + 1 square diagonally outward
DabbabaSlider: moves like a sliding dabbaba
Soldier: slides 2 diagonally forward or non-capture 1 diagonally back
Xiang: slides 2 squares diagonally
StoneDabbaba: slides like dabbaba but only forward or sideways
GooseSlider: forward alfil slide, backward dabbaba slide
StoneElephant: slides 2 squares diagonally forward