One thing I love about Richard Grzela'a 2018 One Page Dungeon Contest entry is how easily it can be dropped into any campaign that is headed towards war, or battles. This is often part of the progression for characters, getting caught up in the politics of neighboring kingdoms or defending against vast hordes of inhuman invaders. The banner at the top of this mountain could very well turn the tide in a losing war, or give the characters an edge before the fighting even begins. An endless variety of hooks could lead your party to this adventure. Perhaps they will keep the banner for themselves, with one party member being saddled with the banner while the others benefit from its effects, or as part of a greater story they might part with it no sooner than they acquire it.
Nice work Richard!