After leaping off many, many locations (higher than this) in Tenebrous Tangle, the spot found to work was at ( 967, 462, 172 ) Copy/waypoint 967, 462, 172 (Gazer Isle & dismount before leaping).
You'll be sent to an instance. This instance functions like a solo, you can bring a merc or a second player.
Note: You have to CoV the other player into your instance to help, and they will not receive an update if they are on the same step.
Click the Eidolon in the center and prepare to fight. These are solo ^ named, however mercenaries do not have the usual ToV buff it seems so bring a friend if you think heals will be an issue.
There are five named that spawn as soon as the previous is killed. The final named has a small knockback. If you get knocked off the side, you'll be zoned back to the center of the platform.
When you are finished fighting, speak to the Eidolon and you'll be ported to an inn in Freeport (The Jade Tiger's Inn) or Qeynos (Fish's Alehouse and Inn), depending on your alignment.
