Simple Idea, but think its a pretty good one.

By collecting all three primal weapons of your specific job, you can fuse them together at the relic blacksmith to create a Ultima weapon.

Pros: +Goes in line with Ultima's lore, absorbing primal powers to create a strong weapon.

+Would inspire people who have previously cleared those primal fights to again run it for the three weapons needed.

The weapon doesn't need to be on Relic +1 Level, but a Item level 80 weapon from it sounds pretty fair.

+Allows your primal weapons to retain use even after obtaining a standard relic.

Thoughts?