Speaking in FFXIV terms if we actually had a true relic in here it should include;

a) Killing the highest raid tier multiple times (x10).
b) Getting the drop (?? item) from the same turn with a very low drop rate.
c) Getting another drop (?? item) from a secondary end game content with the same difficulty level (highest tier) such dynamis.
d) Including high amount of gils in the process.
e) Pushing the exploration, open world contents; collecting items around the world in extremely dangerous areas (raid team required to get through them).
f) Getting highest tier crafters together (those few around if we had a decent crafting system) in order to craft the item itself and to pull overmelds.

Not even the first step should be reachable by casual players with the relic being the highest tier weapon in game raiders slowly gonna collect, step by step.