Quote Originally Posted by Grimwald View Post
Square didn't really call them relic weapons, and these weapons are currently the best in the game, AND Yoshida confirmed that they will be upgradeable in future content and will scale with the level increases that come.

...so, they're pretty good at least for a start.
As it stands, Sphairai is the least impressive relic of the 7. It's technically the best for MNK, but it's not leagues ahead of the competition.