End of immolation

How can I detect it?

The caster doesn't have the buff anymore?

Thats one way to do it.

If im not wrong you can use "Unit is issued a order with no target"
and then conditions use the Immolation order code for order given
Its "unimmolation" i think

First, detect when he starts the effect. Then run a timer that checks every second or so if the unit has the immolation buff. If he doesn't, give actions and pause/destroy the timer.

Just check units orders:
"immolation" and "unimmolation"

Orders are dodgy. Don't do it that way.

The "unimmolation" order is only issued when the player manually casts the spell; e.g. it won't detect when the hero runs out of mana and turns immolation off.

I use immolation all the time for Off and Ons that I want to cost Mana. Just have a periodic Trigger that detects whether or not he has the buff, and then do your things. If you want it to happen specifically when it runs out, you can use a boolean, like so:

there is an event to detect when a unit's mana becomes equal to 0

Yes, but it's a specific unit event. Besides, I may be wrong, but I think a unit's mana doesn't have to reach Zero for Immolation to stop. I think it just has to go below the threshhold (Mana drained each second).

Immolation stops when the unit's mana goes below the 'Buffer Mana Required'. You can always check for the buff though, if you don't like manually draining mana.

It can also be ordered off but not go off if stunned, or some problem like that.

Checking for the buff is the surest way by far.

periodicaly check for the buff ?! (if it's exists...) the best solution... (imho)

//PS lol ^^ i haven't read that xD but well yes.