This is for the world quest called "Assault on the Vestibule" that involves Herculon. This is how it's supposed to work:
- collect 3 [item=176805] (loot from killing mobs)
- collect 3 [item=172451] (collect from anima canisters sitting on the ground around the quest area)
- empower Herculon (right click Herculon the friendly giant mechanical with the grabby hand mouseover)
- assist Herculon (fight mobs while Herculon is walking wherever he's going)
Where I started to have trouble was after I collected the quest items. My quest objectives showed I needed to empower Herculon, and I followed the yellow dot on my minimap right to the middle of the quest area outside. Herculon was there and doing fine and no mobs were attacking him, and he seemed great and fully "empowered" and I couldn't interact with him.
So I came to Wowhead and read a comment that I'm supposed to go into the "cave" where the entrance is at /way 42.7 80.8. (More of an inside temple.) I went there and it was totally empty, no Herculon. I learned from watching a video another commenter linked that I was supposed to find the disabled Herculon there and "empower" him. But he wasn't there.
I went back outside and the yellow dot on my minimap had changed locations. Herculon had already been empowered by another player and was being attacked by mobs. I helped kill the mobs but I didn't get any quest progress because I hadn't "empowered" him yet. I right-clicked on Herculon to "empower" him and then MORE mobs came, I slew a bunch of mobs ("assisted" Herculon) and then the quest auto-completed.
So once you have collected all the quest items, go find Herculon wherever he is, click him to "empower" him, THEN kill mobs to "assist" him, then win.