Reincarnation over cliffs

In one of my maps, I've got some flying heroes, and they've got the reincarnation ability. However, it is bugged, so it doesn't work over cliffs - instead they just die. Anyone know any efficient methods of getting around this? It can't be something that will considerable slow down the map, though.

Dynamicaly create and destroy invisible platforms under such units? That would make the terrain under them pathable for other units as well, though.

If a platform fixes it, you could always make a custom pathing map that has the center pathable and the outside edges marked not walkable so that other units can't use the platform as a 'bridge'.

Another possibility might be to instead use something like the egg ability on the pheonix, but make the egg unit have no model and make it invulnerable (maybe give it the locust abiltiy to make it unselectable, but that might mess up the 'reincarnated' unit also).

Well, locust won't be needed if you use a dummy model with no clickable area instead of no model.

Drag-select would still work, wouldn't it?

Drag select doesn't work if you use a non-existing model.

It's a hero, so it would probably still be selectable by that. Would also make a pheonix-type idea not really practicle. Wouldn't the platform thing mess up the pathing for other units?

It's possible that you can make a pathing texture no unit can stand on because it's too small to make a big enough gap in walls for units to fit through. The only question is, will it be big enough for the nazgul reincarnation to work (if it works at all with this method).

How would I be able to create it there? I can't continually create and destroy it, as that would lag too much (other get arounds better in that case).

It shouldn't be much of a lag issue, but ressurecting heroes with triggers in this case might be better. As long as you don't mind the enemies getting some exp when defeating a nazgul, triggering it should not be hard.

here's an idea:
make two spells that are the same excet: 1 is a passive spell and another be a castable spell that does nothing... so:
keep the passive spell out, when the hero dies, trigger the revival of the hero and then change the spell to the castable spell and make the hero use that castable spell
this way the player can see the cooldown, although the player will be able to click the ability and it will say 'still in cooldown (or whatever)', but it still works
after the cooldown, just change it back to the passive spell

The problem with that is I then have to have a wait - 240 seconds or six additional triggers and quite a lot of new variables.

At the moment I'm trying to get a system to work where by it detects when it dies (reincarnation doesn't count as dying), and then checking whether it has been reincarnated within the last 240 seconds, by an invisible, unselectable unit spawned upon the hero's death, and then moving it to somewhere where it can revive and killing it there (to set off reincarnation). Thus using only one trigger, and only a small wait (because you cannot revive straight after it dies).