Under the Everquest tab in Achievements, then subsection Hunter, you have the "Hunter of the Planes" achievement. This requires that only one item be completed "Hunter of The Plane of Hate" achievement. However, we can not find this requirement anywhere? The TBM section has something similiar but I am not sure that should be linked to the classic list.
You're saying you can't find the Hunter of The Plane of Hate achievement? It's under /ach > Everquest > Hunter. Or did I misunderstand the issue here?
So this must be a TLP thing. I logged into my character on stromm and that toon has it. However, it is still bugged because plane of hate is already the new one so all the mobs needed to do the achiement are active.