For the Z-vanquish. Grab it on every character. Remember how trivially easy Tahnnakai Temple was? It's actually easier to do this region. Just take anyone from Factions with you who has passed Shing Jea Island and there will be zero enemies around.
Just so you understand what that means:
Kill one roaming animal, get vanquish credit.
Gain: 150 Z-copper, 1.5 platinum, and some 10k experience that I'm not sure anyone really needs at this point.
On every character. Hurry though, you have until noon EST (14:00 Guild Wars Wiki time) tomorrow to pick it up. Don't worry about actually having to complete it today, just grab it.