Personally I use ZoG to test my variants, whatever the limitations reported to this package, it is pretty useful to make these tests. Unfortunately it is not so widely available those days.
Interactive Diagram, provided on this website, is a very useful tool too.
Dragonchess is described in WP: https://en.wikipedia.org/wiki/Dragonchess It also has 3 levels subterrannean/earth/air.
Personally I use ZoG to test my variants, whatever the limitations reported to this package, it is pretty useful to make these tests. Unfortunately it is not so widely available those days.
Interactive Diagram, provided on this website, is a very useful tool too.