They should make the upgrade a fun thing to do, gather 3 key materia from some Notorious monster, fuse them into the relic, then soak it into the blood by killing 100 tonberries with it... then at 3:00 midnight time, dip the weapon in Urith's gift pond, which will spawn a monster character with your skill set and class, you must defeat him solo.

Oh wait, that is too much hard work for this game..