In short, I'm trying to get the effects of Fly to work with other move(s). I've copied the HiddenMoveHandlers (both CanUseMove and UseMove) and have gone into the Ready menu and changed
if isConst?(move,PBMoves,:FLY)
to
if isConst?(move,PBMoves,:FLY)||isConst?(move, PBMoves, :WHIRLWIND)...