Flying Press should just deal damage as either Fighting or Flying depending on what would do more in a given situation.
>Use it on a ghost type, ghost is immune to fighting, deal damage as flying
>Use it on a steel type, steel resists flying but is weak to fighting, deal damage as fighting
>If the target is equally weak to both, default to fighting type, unless user is holding an item that boosts flying type damage or target is holding an item that reduces fighting type damage