Legendary Defender question

I've read all the information I've been able to find regarding the Legendary Defender of Ascalon title. There's a lot of info out there and it's answered all my questions except one:

About death leveling...

When a foe has leveled from X number of my deaths and I zone out of the sector, does that foe retain the gained level(s), or when I return to fight him again, will he have reverted to his original level?

I ran a brief experiment, with a level 1 moa outside Barradin. I leveled him until 2, the left the zone. Upon my return, I found 4 moas that were all level 1.

Before anyone says, "well, doesn't that answer your question?", I just want verification/confirmation that this is in fact so, and that I just didn't miss something.

If the creature does revert to its original level, that means I have to death level a creature to the point where it will give me experience each and every time I zone, I assume. Which would explain why it's a good idea to gather several creatures for the exercise.

Before I begin this arduous process, I just want to ensure I've got the facts straight... thx.

If, for instance, you map to Barradin's Estate after levelling a Strider, it won't retain its level. You must kill the Strider while in that instance. Changing maps completely resets the spawns.

On a side note, don't death level Striders. Farm Charr bosses until you hit lv16 then death level Charr patrols in The Northlands. That seems to be the most time-efficient method.

When you leave a zone everything that you did in that zone gets reset. So no, if you death level a monster and leave the zone, the monster will revert to its original level.

Ugh. I was afraid of that, but it makes perfect sense. Thanks for the replies.