That is a really nice 59 DK. I played 59s during the 3.2 dark ages, and only two DKs dared to get on the field on a regular basis (because they were hard to use after the XP-off patch hit), and that wasn't one of them. That likely means whoever Jwillix is, they geared up between the 3.0 release, and the 3.2 XP-off patch. The Zandalar farm was a royal pain in the butt -- I spent more time getting my 2-piece for a 59 then I did for the entirety of leveling and gearing other twinks.
I recently made that Death Knight TBH. I got into 59 about 16 months ago, so I never experienced the Zanda farms
I believe the Zanda gear was class specific: therefore, I don't think Death Knights could have obtained it?
And the rogues name is visible if you look close enough too
I believe the Zanda gear was class specific: therefore, I don't think Death Knights could have obtained it?