A question on Sylvanas' Ultimatum Spell

I've a question on Sylvanas' (undead) Ultimatum Spell (don't know the english name for that spell).
How can I change that spell so that the unit I get with this spell only exists for a certain time? I didn't find anything in the object editor.

Please help me!

you mean charm? Do a trigger that when it fires. Attach a timer to that unit. That will make the unit die after the timer. Or you want control to be given back to the player?

Ok that's what I wanted. I'll try that. But is it possible to do it without triggers? (because I want to make a campaign and I'm to lazy to create that trigger in each level)

You only need to c&p it from level to level. In fact, you can make a category "triggered spells" and c&p the whole category from map to map.