Well Dinah, I tried synthesis. I think I did a good job with it.
Edge's sword: I added a stun effect to it, and increased it's HP damage by 5%.
Reimi's bow: I've added a silence effect, increased HP damage by 5%, and added a freezing effect.
Bacchus's arm cannon: I synthesized his the most, I think. MP cost is reduced by 10%, I've added a stun effect, increased HP damage by 5%, and I've added a paralysis effect to itI've.
Sarah's staff: I've added a water element to it, I've added a freezing effect to it, I've added a silencing effect, And I've added a Pumpkin effect to it.
Well, did I do a good job? That's all I synthesized, my main party's weapons. But I'll work on synthesizing more later on.