what sotonin said above
Sorry, I thought we were talking about different areas on the map, and not flying above the current spot
Also the terrain would have to be “aware” of the other terrain around it. This is not an easy task. the only element currently that does this in the level builder is the dungeon walls. The elevated tiles would need to realize its elevated and stretch down to connect to the lower tiles. I know i mentioned something similar for creating rivers or creeks and was told it’s a difficult task.
As Feinty implied (even if that isn’t what he meant), does the game care about the “z” component? If the Fangrider were given a z of say 8 or 9 would I need a powered up claymore(?) to reach it? (or a ranged weapon/spell)
only if you set the unit to persistZ (or maintainElevation, or something forget the name of it) which is a special flag. yes… you could be out of range. Which is actually a great idea for an enemy. that can’t be killed by melee only ranged or melee with a special weapon.
a new early game variant on the “lead mob to helpers” since you can’t reach it (with warrior, of course)
So the game can handle “z” (just 'cause we have it didn’t mean it was usable (yet)), which leaves us with the graphics and handling edges (both, as you said). 
yeah that might be cool. flying enemy out of range of warrior attacks. so you have to lead it back to your camp where there’s a row of archers to take it down.
and a new(?) magically effect “levitate/fly”. Levitate your archers so they don’t get squashed. instruct the friendly mage to cast fly on you so you can fly over the hordes of munchkins and attack the boss.
That could easily be implemented. Cool idea.
The game engine runs with a third dimension so that the 2.5D graphics can look cooler, but we decided that all player code should care about is 2D, since it’s a lot simpler, and I think that despite the mad skills of some advanced players, the levels we’re working on now or soon aren’t nearly advanced enough to get to the point where calculating things in 3D is the next step in learning to code. 
That’s why self.distanceTo, collision handling, range checks, etc., all just work in 2D.
Physically speaking, we can easily have cliffs that you can walk off, or be flung off, and we could add fall damage if we wanted. We don’t, however, have good ways to make the art visually make sense for that, except in limited circumstances where you are never falling behind a cliff, only in front of it, and those maps will probably have to be custom drawn. This is giving me a few ideas, though.
Well for it to be drawn maybe have the unit get smaller for the effect of getting farther away