Removing a Training Structure

Thanks in advance to anyone who can offer some help.

I'm trying to make a trigger that works like so:

+Event
-A unit owned by Player X dies

+Condition
-Dying unit is a Hero

+Action
-Create one Essence on position of dying unit.

This part works fine. The essence is a custom unit based off of
an Altar, and serves to make the downtime of running your Hero back
to the death spot.

The problem is getting rid of the Essence in a certain manner.
I'm not sure what variable I could use, I tried one, but when
multiple essences are up the status will change to the newest one.
What is a good trigger that will remove the essence once the hero
is revived, without affecting any others in existance?

When the Hero dies, and the Essence is created, save that Essence in a variable specific to the Hero that died.

Assuming I didn't completely miss the point of your question.

(I really like this idea though, btw.)

EDIT: Let's just assume you're using a standard multiplayer style map, where a player can summon any Hero, but only one of each type. (This is even EASIER if the player only has ONE Hero, or even moreso if you give the player a specific Hero.)

Make the variables:

HeroPaladin
HeroPaladinEssence
HeroArchmage
HeroArchmageEssence
HeroMountainKing
HeroMountainKingEssence

When a Hero is created, see what type it is (through conditions) and slam it into the appropriate variable.

Then the Hero dies, see what type it is (again), and then create the Essence, and save the Essence into the appropriate Essence variable of the Hero that died.

Then when the Hero is revived, use that specific variable to get rid of that specific Essence.

Again, that's just my generic version, since I have no clue about your map. Hope it helps in some convoluted way.

Ah yes, I think that would work, thanks, its one of the last things I need to fine tune on my map. As for the heroes used on my map, it does only allow one of each Hero type, sort of. You start off with a pre-set hero, but you can also build the other normal heroes that come along with the race you choose. There are also custom heroes purchasable (not cheap) at the harder to reach mercenary camps.

I guess I'll take a second to explain further what my map is, in case anyone wants to comment on it. It is basically an RPG, but I added in a competitive element. You control an expedition force of your favorite race, where you can ally with the citizens of Iskan (the map location) or with the Chaos forces intent on ending the world (yay). You can also be an ally or enemy with your fellow players, I added some custom chat string options to acheive this (allying with both PC's and the CPU). You can also customize the food cap/monster respawn/difficulty.

The plot is a little more complicated to explain, but I think any RPG fan will appreciate it. Basically your expedition is investigating why Iskan is ground zero for odd weather and an unstable day/night cycle that is spreading beyond the country. I made what you can actually build or tech to very limited so the focus is more on the hero, who can hire somewhere around 100 different types of mercenaries and discover tons of custom items.

I added in a couple custom tracks barely keeping the map under 4 MB (the only downside). There is a ton of other stuff in it, my custom units/items are both maxed out, several bosses and mini-bosses, etc. Now just to finish off that essence stuff.