When Anet finally decided to nerf the champion train in Queensdale - meaning players would finally be able to explore the zone without being run over various bots, farmers, and power levelers in the neverending Zerg Rush.
The end of Dragon's Reach: Part 2 involves the Player Character going up against the Shadow of Mordremoth and driving it away. Alone. In other words, you beat Mordremoth's equivalent to the Shatterer, Tequatl the Sunless, and the Claw of Jormag all by yourself and live to tell the tale.
To make it even better, your character explicitly compares it to Blightghast, the champion of Zhaitan that took over Claw Island and required the combined efforts of all three Orders to take down. This time, you're stranded alone with the dragon. And you win. But the real kicker? Blightghast also killed your mentor. In a roundabout way, It's Personal.