Serious, maybe confusing question.

To avoid confusion, I have Prophecies and Factions, and a buddy code for Nightfall (explained later)

OK, so today is halloween, and I was waiting in LA with my warrior, until I see this guy selling Nightfall trial, or buddy if you will, codes. He seemed like an honest guy, so I bought a code for 1k. So I log out, put the code on and it works.

I originally wanted to buy the code so my warrior could also get the witch hat (or wizard hat as I like to call it for males) but then I realised, what if I made a dervish, got the hat and went to Tyria/Cantha?

So, I quickly made a dervish at 5:54 and rushed through Chaubek into Kamadan. Sure enough, he got the witch hat.

Now, my main question is, if I plant him in Tyria or Cantha can I still play him after the trial key has ended?

Now I thought I could, because it isn't Nightfall content, but then again it's a dervish which is Nightfall content.

I asked the seller and he said I should contact Anet. What are your thoughts on the matter?

I think it'll be the same as any other preview event, any character slot containing characters from a preview/trial event, will be locked after the limit is up. You can still play your other characters, but that individual character slot will only be available after you've purchased the retail key.

Basically it's not based on where you left your character, its where you "created" them.

I'm confident that you cant. dervish character IS nightfall content. the char would lock. remove gold and items off of it before the trail ends, cause you will not be able to get it untill you'll buy nightfall.

The preview key is to let you try Nightfall. After it's over, you need to have copy of Nightfall in order to use that character. Otherwise, it will be lock out and you can't use them.

OK, so lets assume I played Nightfall with my warrior, who is Tyrian born. Say I get to Mouth of Torment then the trail key expires. Where would he go? And so, if I add another trial key, would he still be at Mouth of Torment?

Just an assumption here, but I don't think you can add multiple buddy/trial access keys to the same account. Who would bother buying a retail key if you could do that more than once? Well, besides the guy that gave you the trial keys.

Your warrior would probably be sent back to LA or your guildhall, he won't be stuck in Mouth of Torment.

Yeah, if you have a character who is Elonian born, once the buddy code ends, you won't be able to access him until you get a retail key. Think of it this way....when the World Preview Event went on, it was sort of like a buddy code. People were able to play the Nightfall content, unlock Nightfall skills, characters, etc.., but once it ended, you didn't have access to them until you got Nightfall. If you have a Tyrian or Canthan born character that goes over to Elona and is there when your buddy code ends, I'm about 99.99% positive you're character will automatically be taken to your guild hall. If you want to put this all behind you, I recommend just buying NF because it is WELL worth it!!