In my battle against Sae, I actually my Soma. I didn't know it's a rare item in the game. Truth is, I don't really need to use the item in my battle against Sae but I just decided to use it just to be safe and doesn't want to risk the fight. I kinda overestimate the boss fight. I thought I should replay the save before I fought Sae and this time beat her without using Soma but then I feel lazy fighting her all over again. Should I go back to my previous save or should I progress? I'm at around level 52 when I beat her.

@crayzor: I doubt you'll be challenged by the rest of the game, so it's not a big deal. There are other skills and items you can utilise later on.

I think I sold them all.

They're nice to have for the very very, very end boss just in case. But you can definitely get through that fight without one

It's the classic Megalixer conundrum. I saved all my Soma's until the end of the game, thinking there would be a special occasion I would need to burn them on. Only used one in the final boss battle. Use them whenever you need to.

I saved mine for the final/true ending boss purely so I could burn through all of my SP as much as I wanted, but I don't really think they're needed. By that point you have lots of other items and skills to support your team.

If you have access to curry and coffee, it should be ok. If not, just grind the difference.

ABS, Always Be Soma'ing