Cliff Climb

<spoiler> To solve this properly you need to watch the event video. The fireworks give you the path to climb.

left right right left right left left right left

When you make it to the top, you find a letter.

Once I got this, I looked up Percy climber disappear (since the theme of this box is disappearing) and came back with this page Percy Fawcett

Which at the bottom has a reference to the letter pictured above with the same wording.

That brings you to the posted answer "Percy Fawcett" </spoiler> <spoiler> Percy Fawcett </spoiler>