Help me with trigger!

[Mr.Banankaka]

I have a trigger problem. I don´t know how to make a unit that never accually a trigger to leave the region when it have been there for 30 seconds. Is there even possible to make such a trigger unless the unit has´nt entered the region?

 

[Vulcansurge]

Just make a trigger at map initialization that moves it somewhere else and quickly move it back. Or be even more efficient and place it outside on the map the region and then move it in there.